How to Control Your Cortisol & Overcome Burnout

In this episode, I explain cortisol and science-based protocols for properly setting your cortisol rhythm, which can significantly increase your daytime energy, focus, mood, and stress resilience, while also improving your sleep quality. Most people mistakenly think cortisol is bad, and many assume their levels are too high, when in fact many health and performance challenges simply stem from a disrupted cortisol rhythm. Getting your cortisol rhythm right can be transformative for your health and performance. I outline behavioral, nutritional, and supplement-based strategies to raise or lower your cortisol levels at the appropriate times of day and night. I also provide specific protocols for overcoming burnout. If you’re dealing with stress, low energy, hormone or sleep challenges—or simply want to optimize these for the sake of your physical and mental health and performance—this episode offers science-backed protocols to help. Read the the episode show notes at hubermanlab.com. Thank you to our sponsors AG1: https://drinkag1.com/huberman Carbon: https://joincarbon.com/huberman BetterHelp: https://betterhelp.com/huberman David: https://davidprotein.com/huberman LMNT: https://drinklmnt.com/huberman Timestamps (00:00) Cortisol (1:29) Stress, Tool: Daily Cortisol Rhythm (3:16) Cortisol & Directing Energy, Glucose, Adrenals (6:39) Sponsors: Carbon & BetterHelp (10:14) Daily Cortisol Phases & Rhythm, Waking Up & Cortisol (17:55) Cortisol Release & Regulation, Hypothalamic-Pituitary-Adrenal (HPA) Axis (24:57) Rapid & Delayed Stress Response, HPA Axis (28:42) Bright Light & Cortisol Release, Tool: Increase Morning Cortisol & Sunlight (36:58) Sponsors: AG1 & David (39:48) Viewing Bright Light & Mood, Depression, Seasonal Affective Disorder (SAD) (41:44) Increase Morning Cortisol, Tools: Hydration, Delaying Caffeine Intake (49:30) Exercise, Entrainment Cues & Cortisol Rhythm, Tool: Boost Energy & Exercise Schedule (57:52) Does Deliberate Cold Exposure Increase Cortisol?, Energy & Mood (1:01:19) Sponsor: LMNT (1:02:51) Increase Morning Cortisol & Nutrition, Grapefruit, Black Licorice (1:11:34) Afternoon & Evening Cortisol Rhythms, Sunlight, Screens (1:14:30) Lower Evening Cortisol, Tools: Dim Lights, Light Color (1:20:54) Lower Evening Cortisol, Tools: Caffeine Timing; Stress Response & Exhales; Starchy Carbohydrates (1:30:42) Low-Carb Diets & Cortisol, Metabolic Syndrome (1:35:30) Evening Exercise & Cortisol, Tool: Spike Your Morning Cortisol (1:44:32) Supplements to Reduce Cortisol, Ashwagandha, Apigenin, Magnesium (1:50:57) Burnout, Cushing's & Addison's, 2 Burnout Patterns (1:55:23) Early-Phase Burnout, Tools: NSDR/Yoga Nidra, Boost Morning Cortisol, Caffeine (2:01:35) Late-Phase Burnout, Tools: Reduce Evening Cortisol (2:08:02) Age, Male vs Females, Lifespan, Cancer; Menopause; Brain Health (2:13:41) Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, Sponsors, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter Disclaimer & Disclosures Learn more about your ad choices. Visit megaphone.fm/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Andrew D. Huberman?

  Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life.

• 0:09Andrew D. Huberman?

  I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are discussing cortisol, in particular, how to control your cortisol in order to avoid burnout, or, should you already be feeling burnt out, how to overcome burnout. Now, it's hard for me to overemphasize just how important cortisol is. In fact, in the late stages of preparing for this episode, it dawned on me that if ever there were an episode of the Huberman Lab Podcast that people could benefit from in terms of their health and well-being, this would be that episode. And I say that because, as you'll soon learn, cortisol, the biology of it, how it impacts your mood, your sleep, your immune system, your overall feelings of well-being, not just in the moment,

• 0:54Andrew D. Huberman?

  but over the long term, and your ability to control cortisol at different portions of the day and night, makes it one of the most, if not the most powerful levers for your health and well-being. So I'm very excited to get into the material for today's discussion about cortisol, how to control it, and how to avoid and overcome burnout. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, today's episode does include sponsors. Okay, let's discuss cortisol. Now, I believe that most people have heard of cortisol, and most everyone that hears the word cortisol hears it somewhere nearby the word "stress."

• 1:38Andrew D. Huberman?

  And it makes sense why you would hear about cortisol in that context, because indeed, cortisol is a hormone that's made and released in response to stress. Now, the problem with thinking about cortisol simply as a stress hormone is that it's doing a lot of other things unrelated to stress that are super important and positive for you. However, it all depends on how high your cortisol levels are and when. So during today's discussion, there's going to be a very prominent theme, which is your cortisol rhythm, or more particularly, your 24-hour, so-called circadian rhythm in cortisol. And here's the important first thing to remember. You want your cortisol high early in the day, shortly after waking, and you want your cortisol low in the hours right before sleep

• 2:22Andrew D. Huberman?

  and in the first hours of sleep. If you remember nothing else from this episode, please remember that because if you get those two things correct, everything else in terms of health and wellness and performance, all of that will be reinforced by getting your cortisol rhythm correct. So today I will explain how to get your cortisol rhythm correct. I will also explain what stress does to cortisol in the short term, which turns out to be good for you, and in the long term if you're dealing with long bouts of stress associated with what eventually becomes burnout. So it's also important for me to point out that if you're already feeling wired and tired and burnt out, if you don't have energy in the morning, or if you somehow have low energy all day, but then at night you can't sleep, this is very typical of burnout, or if you have morning anxiety,

• 3:07Andrew D. Huberman?

  literally all of that can be resolved, perhaps not entirely, but mostly, and in some cases entirely, by fixing your cortisol rhythm. Okay, so to understand and control your cortisol, the first thing you really need to know is that cortisol, again, is not a stress hormone per se, rather cortisol is involved in deploying and directing energy to tissues that need it most. Okay, I'll say that again. Cortisol is not a stress hormone per se. Cortisol should be thought of as a hormone that causes the deployment of energy into the body and helps direct that energy to particular tissues, especially your brain, in order to deal with, yes, stressors, but all sorts of other things that demand your energy.

• 3:52Andrew D. Huberman?

  So, the way to think about cortisol is that it causes the release of glucose, blood sugar into the bloodstream. And it does that by controlling energy released from the liver and from the muscles, and it literally can cause the release of glucose from individual neurons, nerve cells in the brain. But cortisol is not made in the brain. Cortisol is made in your adrenal glands. And of course, the adrenals are associated with adrenaline, also called epinephrine. Those are the same thing, by the way. Epinephrine and adrenaline. And your adrenals will release epinephrine, aka adrenaline, in response to a stressor very quickly. Your adrenals can also release cortisol in response to a stressor, but it needs to make that cortisol first and then release it.

• 4:35Andrew D. Huberman?

  So cortisol acts on a slightly slower timescale to deal with stress. And as I mentioned before, cortisol isn't just about stress. Cortisol is also about generating energy to deal with pretty much anything that requires energy. So when you need energy to deal with stress, to deal with getting out of bed in the morning, to deal with a hard school task, work task, relationship task, drive your kids to school, whatever, cortisol needs to be released. Okay, this is a very different mental framework around cortisol than we're used to hearing. We normally hear elevated cortisol, I'm releasing cortisol, my cortisol is too high. You need cortisol released in order to get glucose, blood sugar into the bloodstream. Now cortisol is unique compared to, say, adrenaline or norepinephrine,

• 5:19Andrew D. Huberman?

  because cortisol is what's called lipophilic, meaning because cell membranes are lipid, fat, and cortisol is lipophilic, it can move through cell membranes. And what that means in the functional context, what it means for you, is that cortisol is released from the adrenals, circulates in the blood, just like adrenaline would. But unlike adrenaline, it can cross the blood-brain barrier, and it really likes to do that because there are a lot of receptors for cortisol in the brain, in particular, in a region of the brain called the hippocampus, which is involved in memory. Now, we'll come back to the hippocampus later because the hippocampus is vital for understanding what happens during situations of chronic stress and why cortisol can be dysregulated under conditions of chronic stress. But for the time being, let's go back to thinking about cortisol

• 6:04Andrew D. Huberman?

  simply as a mode of releasing glucose into the bloodstream. Cortisol releases glucose into the bloodstream. Much of that glucose is going to be directed toward brain energy, so that neurons, nerve cells, can use it to think and to deal with whatever happens to be confronting you during your day, good or bad, stressful or non-stressful. So one of my biggest wishes for today is that you, and hopefully the rest of the world, will eventually come to adopt the understanding that cortisol is not a stress hormone. Yes, cortisol is involved in stress, but cortisol's main job is to deploy energy. It's an energy-producing hormone, in particular, a brain-energy-producing hormone.

• 6:44Andrew D. Huberman?

  I'd like to take a quick break and acknowledge one of our sponsors, Carbon. Carbon is a diet coaching app built by nutrition expert Dr. Lane Norton. I've used Carbon for more than three years now, and I have to say, having been interested in fitness and in my nutrition for more than three decades, it's among the most powerful tools for nutrition coaching and effective weight management that I've ever encountered, especially if your goal is like mine, which is to maintain or build muscle while also losing fat. Now, I'm turning 50 years old this September, and even though I consider myself in pretty good shape, and I've been training for a long time and trying to eat right, one of my goals is to hit 50 in the absolute best shape of my life. To do that, I'm dialing in my nutrition using Carbon with the goals of increasing

• 7:25Andrew D. Huberman?

  my muscle mass, increasing my strength, while also decreasing my body fat. I've been raving about the Carbon app to friends and to family and to members of my Huberman Lab team over the last few years, and everyone who's joined me and using it has found it to be tremendously useful. In fact, some of those people are going to join me in my approaching 50 fitness goals and body composition goals. My birthday is September 26th, and so I'd like to invite you to join if you would like to improve your body composition and fitness to also use the Carbon app. Now, there are a lot of apps out there that are focused on fitness and nutrition, but what makes Carbon different is that it doesn't just hand you a one-size-fits-all plan. It actually learns your metabolism over time, and it adapts your program based on your results. It also allows you total flexibility in how you eat.

• 8:10Andrew D. Huberman?

  If you're plant-based or you're keto, high carb, low carb, anything in between, or even if you switch back and forth between different diets, Carbon works around your preferences. The other thing I love about Carbon is that it easily adapts to whether you're the type of person who likes to put in the specific brand and the exact number of ounces or grams of food that you ate, or if you tend to be a little bit looser about that, like you ate half a handful of almonds or something like that, it can learn and adapt to that and still give you accurate recommendations. So if you're looking to take a smarter, more personalized approach to your nutrition, I can't recommend the Carbon app enough. To try Carbon, you can go to joincarbon.com/huberman. While Carbon does not typically offer trials or promotions, they've agreed to give a free seven-day trial to all Huberman podcast listeners.

• 8:55Andrew D. Huberman?

  Again, that's joincarbon.com/huberman to get a seven-day free trial. Today's episode is also brought to us by BetterHelp. BetterHelp offers professional therapy with a licensed therapist carried out entirely online. I personally have been doing therapy for well over 35 years. I find it to be an extremely important component to overall health. In fact, I consider doing regular therapy just as important as getting regular exercise, including cardiovascular exercise and resistance training, which of course I also do every week. There are essentially three things that make up great therapy. First of all, it provides the opportunity to have a really good rapport with somebody that you can really trust and talk to about essentially any issue that you want. Second of all, it can provide support in the form of emotional support or directed guidance,

• 9:40Andrew D. Huberman?

  or of course, both. And third, expert therapy should provide you useful insights. Insights that can help you improve in your work life, your relationships, and in your relationship with yourself. With BetterHelp, they make it very easy for you to find an expert therapist who you resonate with and that can provide those three benefits that come from expert therapy. Also, because BetterHelp therapy is done entirely online, it's very time efficient and easy to fit into a busy schedule. There's no commuting to a therapist's office or sitting in a waiting room looking for parking, any of that. You just hop online and you do your session. If you'd like to try BetterHelp, you can go to betterhelp.com/huberman to get 10% off your first month. Again, that's betterhelp.com/huberman. Okay, so just a couple of minutes ago, we were talking about how cortisol needs to be

• 10:23Andrew D. Huberman?

  high in the morning shortly after waking and low in the nighttime and certainly while you're asleep. Except for, as it turns out, in the final hours of sleep, you actually want your cortisol rising. So we need to take a step back and ask, why is cortisol released? When is it released? How is it released? Because understanding that gives us control over cortisol at any time of day or night. So rather than just list off a bunch of things that you can do to increase your cortisol or decrease your cortisol, which I'd love to do frankly, but the problem with that is if I do that, it doesn't take into account that your levels of cortisol are constantly changing across the 24-hour cycle. So if you don't understand that endogenous 24-hour rhythm in cortisol, not just knowing

• 11:07Andrew D. Huberman?

  that it's high in the morning and lower at night, if you don't understand how that's regulated, you won't know which protocols, which tools... To apply when, but if you can understand how that rhythm is generated and how cortisol is released in response to short term events like stress, but also the desire or need to exercise, the desire or need to focus. If you can understand those things, how cortisol is released in the short term and across the 24 hour cycle, how it literally regulates itself, then you will have immense control over cortisol across the 24 hour cycle from day to day and from moment to moment. Okay, cortisol is a corticosteroid hormone. Yes, it's a steroid hormone, just like testosterone is a steroid hormone, just like estrogen is a steroid hormone.

• 11:49Andrew D. Huberman?

  Steroid hormones are derived from the molecule cholesterol. And there are a bunch of biochemical steps that take you from cholesterol to cortisol, or from cholesterol to testosterone, or from cholesterol to estrogen. Scientists have long known that cortisol is not at the same level throughout the 24 hour day. In fact, there's a quite classic study now that examined the 24 hour pattern of the episodic secretion of cortisol in normal subjects. And what they found is that there are essentially four phases of cortisol levels. I'll just read off what these different phases are. Phase one is a six hour period of what they called a minimal secretory activity, meaning when cortisol is not released very much, that starts four hours before and

• 12:34Andrew D. Huberman?

  continues until two hours after lights out for sleep. Okay, starts four hours before and continues until two hours after you turn your lights out to go to sleep. The second phase of cortisol, in which the levels are quite different than in the first phase, is a three hour period, which they called the preliminary nocturnal secretory episode, but we can simply call the third to fifth hour of sleep. So in your third to fifth hour of sleep, you have a second phase, and this phase they call the preliminary nocturnal secretory episode. And this is when

• 13:12Andrew D. Huberman?

  Cortisol is slightly starting to rise, just a little bit. In the first phase cortisol is very, very low. Or ideally, you want cortisol very low. So this is under normal, healthy conditions in that first phase. The four hours before until the two hours after lights out. Cortisol is going to be very low and it's going to stay low. And then in the second phase, it's going to slightly rise into the third and fifth hour of sleep. Then in phase three, which here is listed as a four hour period, but the exact duration is going to vary. You have what's called the main secretory phase of cortisol. This is when cortisol is increasing very, very fast. And this occurs, believe it or not, during the sixth, seventh and eighth hour of sleep. Now, you might say, I only sleep six hours.

• 13:56Andrew D. Huberman?

  So do I get that fast rise in cortisol? Guess what? You don't. If you sleep seven hours, you only get a portion of that fast rise in cortisol. If you sleep eight hours, you get the full duration. And if you sleep nine hours, yes, your cortisol will continue to rise. So the idea here is that in the very final hours of sleep, your cortisol is starting to rise quickly. This is the time of sleep that correlates with when REM sleep, rapid eye movement sleep is most abundant. Okay, so in the early part of your sleep night, slow wave deep sleep is most abundant. This is when growth hormone is released. This is when your metabolism tends to be very low. Think about it. Metabolism low means low requirement for blood glucose. And it's associated with low cortisol levels.

• 14:40Andrew D. Huberman?

  Starting to make sense. In the last portion of sleep, the final, say, two to three, or if you sleep nine hours, four hours of sleep, you have rising levels in cortisol. We know that's associated with REM sleep, rapid eye movement sleep. And we know that REM sleep is a time of robust brain activity that even is greater than what occurs during wakeful states. What do you need for robust brain activity? You need energy. Where's that energy coming from? Blood glucose. How is that blood glucose deployed? Because cortisol causes its deployment. Okay, it's starting to make sense now. And then there's a fourth phase of secretory, what they called secretory activity of cortisol, which is after you wake up.

• 15:25Andrew D. Huberman?

  Starts right after you wake up. And I'm going to add another little sub-phase to this, not to complicate it, but because it's a very powerful time each day, which is the first hour after waking. From the moment you open your eyes and you decide to get out of bed, doesn't matter if it's because of an alarm clock or it's because you just naturally woke up. That first hour is a very special hour because it's a time in which you can further amplify the increase in cortisol. After that first hour, or certainly after about 90 minutes, you don't have that opportunity again until the next morning. There are things you can do to reduce your cortisol or to slow its decline into the afternoon and evening. But that first hour after waking is critical. Okay, so to step back now, what do we have? Let's talk about this in real world terms.

• 16:11Andrew D. Huberman?

  In the hours right before falling asleep and in the first hours of sleep, your cortisol is very low, ideally. This is the ideal case scenario for health, for your mental health, for your physical health, for performance. Then cortisol starts to rise on its own. You're not doing anything to make it rise. It starts to rise in particular as you transition from the middle of the night toward the end of your sleep night. And then just before waking, your cortisol is sharply rising, steep, steep slope of increase. And then as you wake up, boom, you have this hour-long or so opportunity to further increase your cortisol and you definitely want to increase your cortisol further during that first hour. And then about three, four hours later, so for most people that would be late morning or around noon time,

• 16:53Andrew D. Huberman?

  your cortisol levels are slowly going to start to decline. However, if they decline too slowly, that's bad.

• 17:02Andrew D. Huberman?

  If they decline too sharply, that's also bad. So the picture I'm trying to draw for you here is you want a really sharp spike in cortisol as you arise in the morning. And then you want that to taper off somewhat gradually. So not too steeply, not too gradually into the afternoon such that by three, four hours or so before sleep, your cortisol levels are low, low, low, low, low and continuing to fall lower before they start up again the next morning in anticipation of you waking up. And if you haven't already caught on to this yet, you literally wake up because of a rise in cortisol. It's called the cortisol awakening response or CAR, C A R, cortisol awakening response. The importance of cortisol for waking up and for feeling alert early in the day cannot be overstated.

• 17:46Andrew D. Huberman?

  This is the anchor point at which you have control over your cortisol levels. And if you do things right in that first hour or 90 minutes of the day, you're going to set yourself up for an overall healthy pattern of cortisol release at night as well. Okay, so stay with me here as we get into a bit of mechanism as to how this cortisol rhythm is generated. Because if you can understand that, it gives you immense control. Okay, so let's talk about how cortisol is generated and how it self-regulates itself. So cortisol again is made and released from the adrenals, to be specific, from a particular middle layer of your adrenals where a particular category of cells that make cortisol reside. Those cells need the instruction to make and release cortisol and that instruction comes in the form of a hormone.

• 18:29Andrew D. Huberman?

  So the whole story starts up in the brain in an area of the so-called hypothalamus. Hypothalamus is a little structure. It's actually quite small, the size of about two small marbles sitting above the roof of your mouth. And they sit next to this thing that we call a ventricle, which is where the cerebrospinal fluid circulates. Now, this turns out to be important because the cerebrospinal fluid gives the brain or the neurons there, information about the chemistry of the body. It gives the neurons there information about what's in the bloodstream too, because the the area there allows blood vessels to get closer to the neurons and expose the neurons to more of what's going on in terms of the body chemistry than neurons located more deeply in the brain.

• 19:11Andrew D. Huberman?

  So it's nice that the neurons that we're going to talk about now reside in an area of the hypothalamus called the paraventricular nucleus. Para means near, ventricular means ventricle, so paraventricular, near the ventricle, where they can access information about the body's chemistry. So there are neurons that reside in the so-called P V N, paraventricular nucleus, and they extend processes into the pituitary gland. The pituitary gland is a little stalk that has a couple of different lobes. Okay, they literally look like little lobes. It looks like if you took a couple cloves of garlic and you held on to their stalks next to one another, those two cloves of garlic, a big stalk and a slightly smaller stalk, it's kind of what the pituitary looks like. And the pituitary actually extends out of the brain.

• 19:55Andrew D. Huberman?

  And the neurons in the paraventricular nucleus release a hormone called corticotropin-releasing hormone, or C R H. Corticotropin-releasing hormone acts on neurons in the anterior pituitary, in that front piece of garlic, and causes the cells there to release a hormone called A C T H, adrenocorticotropin hormone. Okay, I know there's a lot of nomenclature here, but you should know the facts. A C T H is then released into the bloodstream, and it travels down to the adrenals, and it stimulates the release of cortisol. In fact, by binding to something called the melanocortin receptor, which doesn't seem important for the moment, but later when I tell you why people who have chronically elevated cortisol get what's called hyperpigmentation, they get some pigmentation on their face

• 20:39Andrew D. Huberman?

  that's kind of blotchy, right? This is a symptom of something called Cushing syndrome, which is elevated cortisol. It will make sense, melanocortin, okay, it's involved in pigmentation. The melanocortin receptor sits in that middle layer of the adrenals, and A C T H binds to it, causing the synthesis and release of cortisol. Okay, then cortisol in response to stress, yes, but also in response to any time we need to get our energy going, our brain energy, our focus, or, as you learned a few moments ago, any time we need to wake up in the morning, right? Anytime we need to get out of bed, that requires energy, right? In fact, the transition from sleep to wakefulness is one of the biggest requirements for an energy surge, which is why you have the cortisol awakening response.

• 21:23Andrew D. Huberman?

  So cortisol is going to be released into the bloodstream, it's going to cause the deployment of blood glucose, the breakdown of amino acids and other fuels in muscle, in liver, in particular glycogen in the liver. That's going to be released into the bloodstream. And here's the thing, as cortisol is released into the bloodstream, the neurons in the brain that cause the release of CRH, corticotropin-releasing hormone, have access to how much cortisol is in the bloodstream. How? Well, they are paraventricular. Blood vessels and capillaries are also lining the ventricles. So those cells in the paraventricular nucleus have a sort of thermometer, if you will. They're kind of like a thermostat,

• 22:06Andrew D. Huberman?

  paying attention to just how high levels of cortisol are in the bloodstream. So when levels of cortisol in the bloodstream are very low, those cells in the paraventricular nucleus release more CRH to stimulate the release of ACTH, to go to the adrenals, to cause the stimulation and release of more cortisol, driving levels of cortisol up. And by the way, cortisol has a relatively long half-life, so it tends to accumulate in the bloodstream. So as levels of cortisol tend to go up, let's think about that last phase of sleep, maybe, you know, two or three hours before you wake up, cortisol's going up, up, up, up, up. What ends up happening eventually is that the cells in the paraventricular nucleus of the hypothalamus that release CRH hit a point where they realize,

• 22:51Andrew D. Huberman?

  at a biochemical level, that is, they realize, based on receptor saturation and some other mechanisms internal to the cells, ah, cortisol levels are really, really high right now. Let's shut down the release of corticotropin-releasing hormone, which causes a shutdown of the release of ACTH, which causes a shutdown of the synthesis and release of cortisol from the adrenals. So this is what we call a negative feedback loop. And by the way, this is the same way that testosterone works. In many ways, it's the same way that estrogen works, although estrogen's subject to a bit more regulation as well. When levels of the hormone cortisol reach a certain point, a certain threshold, it shuts down its own production by turning off the signals that would cause more of it to be produced.

• 23:36Andrew D. Huberman?

  Okay, so this is a negative feedback loop. Now, that means that cortisol, after reaching a certain high level in the morning, will eventually start to drop off. And those levels will continue to drop off. And should we encounter a need for a lot of brain energy? So it could be a really focused conversation. It could be an exam. It could be you're playing a bout of soccer or you're going to the gym and you need a bunch of energy. You have to rally your, your mind and your motivation to do that. Yeah, you'll get an increase in cortisol. But that little increase in cortisol is like a bump of cortisol that rides on that already dropping endogenous rhythm in cortisol. So by now, it's probably dawning on you that as those levels of cortisol get lower and

• 24:18Andrew D. Huberman?

  lower into the late afternoon and evening, et cetera, those cells in the brain that release CRH are now registering at a biochemical level, at a cellular level, that the levels of cortisol are very low. And so eventually, those levels get low enough that those cells in the paraventricular nucleus go, oh, cortisol levels are really, really low. They're not zero, but they're really low. Let's start releasing corticotropin, releasing hormone, which stimulates ACTH, which stimulates the adrenals. And that's why cortisol starts to rise again late in sleep and into the next morning. Does it make sense? Hopefully, that makes sense. Cortisol is regulating its own production so that it doesn't get too high or too low. And it does that through a negative feedback loop involving these cells in the hypothalamus.

• 25:02Andrew D. Huberman?

  So what I just described was something called the HPA axis. Hypothalamic, H. Pituitary, P. Adrenal axis. Okay? So the HPA axis is important for synthesis of cortisol to generate this 24-hour so-called circadian rhythm. It's also important for the synthesis of cortisol in response to stress, both short-term and long-term. And I'm going to get back to stress a little bit more later, but let's just, for a moment, think about that HPA axis and two things about stress that you can kind of put up on the shelf that will be helpful later as we get into our discussion about short-term and chronic stress. Stress activates the HPA axis, but as you know, stress is a very fast response, meaning

• 25:46Andrew D. Huberman?

  when you encounter a stressor, your heart rate goes up, your blood pressure goes up, your eyes widen, literally, your pupils widen and your eyes widen, and all sorts of things happen in terms of your levels of alertness and attention. That very rapid response occurs also because of the HPA axis, but because of the release of adrenaline, epinephrine, and norepinephrine from your adrenals and also from areas in your brain. That's a very fast thing. It happens within milliseconds. If not milliseconds, certainly within seconds. Just think about if you're walking down the street in a city and a, you know, a car kind of veers onto the sidewalk and you have to jump out of the way. You made the reaction without even basically having to think about it. You get out of the way and your heart rate's up. Everything's happening all at once.

• 26:29Andrew D. Huberman?

  You're completely different state than you were just a few seconds prior even. That's all happening fast because of adrenaline and norepinephrine. Cortisol, yes, will be deployed in response to that sort of stressor. But cortisol needs to be synthesized and then released, and then it causes the release of glucose. And that's going to take some time. In fact, it takes about 10 minutes. So it turns out that can explain a lot of why stress tends to come on very quickly and last rather long relative to the stressor, to the thing like the car that veered up onto the sidewalk. You probably had that experience where something happens that's very stressful, then the stressor is resolved, right?

• 27:11Andrew D. Huberman?

  The car didn't hit you, it didn't kill you, thank goodness, didn't run over your leg, didn't break your leg, thank goodness. But you turn to your friend, you're like, oh my goodness, that was a close call. And guess what? About five, 10 minutes later, you're still kind of stressed about it. Something stressful happened, something real, as we say, happened. And it's hard to just kind of get back to baseline again. And that's because that wave of cortisol comes on a little bit later and it lasts longer, has a much longer half-life than does adrenaline or norepinephrine. So the stress response has this fast aspect to it that's generated through the HPA axis and through, again, release of hormones such as norepinephrine in the brain. Those two things happen in parallel.

• 27:55Andrew D. Huberman?

  By the way, that happens because adrenaline is released from the adrenals very quickly to cause changes in the body, but adrenaline can't cross the blood-brain barrier. And when you need a very fast reaction in order to deal with a stressor, you can't really wait for that hormone to cross from the bloodstream into the brain. So you release norepinephrine from a site in the brain very quickly as well, in parallel with that release of adrenaline. So those two things happen in parallel. Boom, you deal with the stressor, hopefully that stressor is resolved, didn't injure you or worse. But then that wave of synthesis and release of cortisol occurs, blood glucose is elevated, and so it takes a while for stress to come down again. All of that is mediated through the HPA, hypothalamic-pituitary-adrenal axis, as is

• 28:38Andrew D. Huberman?

  the generation of that 24-hour rhythm in cortisol, where cortisol slowly rises and then goes back down. Into the evening and nighttime and so on. Okay. Now, that's the first way that cortisol is synthesized and released. But there's a second way that turns out to be very important. And it involves a structure called the suprachiasmatic nucleus, or SCN. The suprachiasmatic nucleus is your brain's central circadian pacemaker. It's the set of neurons, also above the roof of your mouth, also in the hypothalamus, that basically orchestrates all the activities of all the organs and cells in your body, like an orchestra conductor. Makes sure that your gut cells are active at a certain time, that you're hungry at certain times, you're not hungry at others.

• 29:21Andrew D. Huberman?

  Regulates pretty much everything, including cortisol. And the SCN can control the HPA axis, when it's active, when it's less active, by virtue of connections that run through, if you really want to know the names for you aficionados, through the dorsomedial hypothalamus and then to the paraventricular nucleus. Okay, that's all fine and good. It just means that the HPA axis is subject to immediate control over stressors or other things that require our attention. Again, doesn't have to be stress, could be positive things. As well, the HPA axis is under the control of the SCN, circadian timing, which is what generates that high in the morning, low in the afternoon and evening rhythm. All of that subject to negative feedback.

• 30:03Andrew D. Huberman?

  Controls itself, making sure levels don't get too high or too low for too long. But there's a second pathway, a parallel pathway, as we call it, that is separate from the HPA control over the synthesis and release of cortisol. And this one originates also in the SCN, the suprachiasmatic nucleus, and is relayed through a couple of different synapses, a couple of different junctions, and eventually runs through a nerve pathway that, for you aficionados, is called the splanchnik nerve. All right, kind of cool name, splanchnik nerve, that can cause the release of cortisol, or I should say, the synthesis and release of cortisol. In response to times when you want cortisol to be especially high for a while. Okay, so this is different than the requirement for stress.

• 30:47Andrew D. Huberman?

  You might think, you know, we want cortisol to be high in response to stressors. No, your brain and body are really smart. They're really, really smart. When you encounter a stressor, you deploy just as much cortisol as your body thinks you might need in order to resolve that stressor, and probably not a whole lot more. And because cortisol lasts a while, as we just discussed, it gives you an opportunity to have more brain energy, bodily energy, to resolve that stressor. But your brain and body sort of know, at a biological level, that you don't want cortisol too high for too long. That's why you have the negative feedback loop. However, there's a beautiful mechanism, which is this second parallel pathway from the SCN, that allows you to control the amount of cortisol that you release and boost it even further for a long period of time.

• 31:32Andrew D. Huberman?

  Now, when would you want that to occur? You think, like, why would I want that to occur? Maybe in response to a chronic stressor, a very long stressor. Well, actually, you wouldn't want that to happen, because if cortisol is elevated for too long at the wrong times of day or night, you run into all sorts of issues related to immune system suppression, to dysregulation of metabolic function. And this is where we start to hear about some of the more common negative aspects of chronically elevated cortisol, like accumulation of body fat around the midsection, the so-called moon face, you know, the, literally, the rounding of the face and the accumulation of fat in the face. There's usually an accompanying loss of fat in the neck and accumulation of fat around the belly. Nobody wants this, right? Some things like hyperpigmentation and things like that. All right?

• 32:17Andrew D. Huberman?

  But there is a time of day when everyone would benefit from having higher levels of cortisol, not just for a few moments or minutes, but for several hours. And that's the first hour or two, or two and a half, or three, after waking. So while there's this 24-hour rhythm in cortisol, where cortisol is elevated in the morning, there's this unique opportunity of about an hour to two hours, maybe three, immediately after waking, when your SCN can activate this parallel pathway down to your adrenals to cause the release of more cortisol and elevate your morning energy, alertness, mood, and so on. Now you might be saying, wait, this is kind of confusing. The SCN controls the 24 hour rhythm,

• 33:01Andrew D. Huberman?

  but it's also controlling the faster release of cortisol during this, you know, kind of one unique window immediately after waking. It's kind of confusing, right? The SCN's involved in both things. Ah, well, the SCN has access to one particular feature of your external world, of your environment, that no other structure in the hypothalamus has access to. And that's the presence or absence of light. The retina, the light sensing tissue at the back of your eye, contains a bunch of different neurons that sense light, convert it into electrical signals, and hand those electrical signals off to a certain class of cells called the retinal ganglion cells. Retinal ganglion cells project into the brain to allow you to see things, colors, shapes, motion, et cetera. However, there's a specialized subset of those retinal ganglion cells,

• 33:45Andrew D. Huberman?

  called the intrinsically photosensitive melanopsin retinal ganglion cells, that respond in particular to very bright light, or more accurately, to transitions between dimmer environments and brighter environments that last a long period of time, like, for instance, when you go from your eyes closed in sleep to your eyes opening when awake.

• 34:08Andrew D. Huberman?

  Those neurons project directly to the suprachiasmatic nucleus. In other words, your SCN has unique access to information about when the levels of overall luminance in your environment change dramatically, such as upon waking. So here's where I'm going to suggest a protocol, and you've heard this protocol before, I know. The protocol is to get bright light, ideally from sunlight, into your eyes within the first hour of waking, ideally within the first 30 minutes. Ideally, it's from sunlight, so you would go outside, take your sunglasses off. Eyeglasses and contacts are fine, even if they have UV protection in them. Look in the direction of the sun, blink as needed to protect your eyes. Yes, you can do this on cloudy days. In fact, it's more important to do on cloudy days.

• 34:52Andrew D. Huberman?

  Because cloudy days tend to be dimmer overall. And this is a unique opportunity to boost your cortisol levels in that first hour of the day. If you don't have access to sunlight for whatever reason, travel, you live in a cave, time of year, weather, whatever, you could use a 10,000 lux artificial light. These are available online for usually about a hundred dollars or so. These are very useful tools. Some of them are portable. If you're going to do that, I still highly recommend that you get outside and get some sunlight in your eyes as soon as you can, once the sun is out. But for you very early risers that wake up before the sun is out, this is so, so key. And I know I've been talking about this for years on this podcast and elsewhere. And I know I've just been, you know, hitting this like, like a, you know, banging on the same drum over and over again.

• 35:36Andrew D. Huberman?

  But that additional surge in cortisol that can occur only in that first one to say, two or three hours of the day, that's a very special time. Because it's not just about the elevated mood, focus and alertness that you're going to achieve during that time by virtue of getting bright light in your eyes. It's also the case, and please hear this, I want to highlight bold, underline this for you. It's also the case that the higher that first peak in cortisol is early in the day, the better you're setting yourself up for low levels of cortisol later in the evening and at night, which will allow you to fall asleep easily, to stay asleep easily. And now you know why.

• 36:19Andrew D. Huberman?

  The reason why is that negative feedback regulation of cortisol. Think about it. If cortisol gets too high, the system shuts down the release of more cortisol. And what you've done by viewing bright light as soon as possible after waking is to amplify your levels of cortisol, which then are going to trigger that negative feedback loop and going to cause cortisol to gradually decline from the late morning, perhaps starting around, mm, 10 a.m., 11 noon, depending on when you woke up, of course. Dropping, dropping, dropping into the afternoon. So you have plenty of energy into your early afternoon, late afternoon, but by evening and nighttime, your cortisol levels are low.

• 37:03Andrew D. Huberman?

  I'd like to take a quick break and acknowledge our sponsor, AG1. AG1 is a vitamin, mineral, probiotic drink that also includes prebiotics and adaptogens. As somebody who's been involved in research science for almost three decades and in health and fitness for equally as long, I'm constantly looking for the best tools to improve my mental health, physical health, and performance. I discovered AG1 back in 2012, long before I ever had a podcast, and I've been taking it every day since. I find it improves all aspects of my health, my energy, my focus, and I simply feel much better when I take it. AG1 uses the highest quality ingredients in the right combinations, and they're constantly improving their formulas without increasing the cost. In fact, AG1 just launched their latest formula upgrade.

• 37:46Andrew D. Huberman?

  This next-gen formula is based on exciting new research on the effects of probiotics on the gut microbiome, and it now includes several clinically studied probiotic strains shown to support both digestive health and immune system health, as well as to improve bowel regularity and to reduce bloating. Whenever I'm asked if I could take just one supplement, what that supplement would be, I always say AG1. If you'd like to try AG1, you can go to drinkag1.com/huberman. For a limited time, AG1 is giving away a free one-month supply of omega-3 fish oil along with a bottle of vitamin D3 plus K2. As I've highlighted before on this podcast, omega-3 fish oil and vitamin D3 K2 have been shown to help with everything from mood and brain health, to heart health, to healthy hormone status, and much more.

• 38:29Andrew D. Huberman?

  Again, that's drinkag1.com/huberman to get a free one-month supply of omega-3 fish oil plus a bottle of vitamin D3 plus K2 with your subscription. Today's episode is also brought to us by David. David makes a protein bar unlike any other. It has 28 grams of protein, only 150 calories, and zero grams of sugar. That's right, 28 grams of protein and 75% of its calories come from protein. This is 50% higher than the next closest protein bar. David protein bars also taste amazing. Even the texture is amazing. Favorite bar is the chocolate chip cookie dough. But then again, I also like the new chocolate peanut butter flavor and the chocolate brownie flavored. Basically, I like all the flavors a lot. They're all incredibly delicious. In fact, the toughest challenge is knowing which ones to eat

• 39:14Andrew D. Huberman?

  on which days and how many times per day. I limit myself to two per day, but I absolutely love them. With David, I'm able to get 28 grams of protein in the calories of a snack, which makes it easy to hit my protein goals of one gram of protein per pound of body weight per day. And it allows me to do so without ingesting too many calories. I'll eat a David protein bar most afternoons as a snack, and I always keep one with me when I'm out of the house or traveling. They're incredibly delicious. And given that they have 28 grams of protein, they're really satisfying for having just 150 calories. If you'd like to try David, you can go to davidprotein.com/huberman. Again, that's davidprotein.com/huberman. Now, we're going to talk about some other things that you can do to boost your morning cortisol in a meaningful way.

• 39:58Andrew D. Huberman?

  However, before I do that, I have to say that this viewing morning sunlight thing, or bright light from a 10,000 lux artificial source, the increase in cortisol that it provides, and therefore, the increase in energy and mood and focus, et cetera, is very significant. It's been shown to quickly increase cortisol levels by up to 50%, 5-0%. And in fact, it's clinically significant. People who live in areas of the world where during winter, there's very little availability of sunlight and just rely on artificial indoor lights often suffer from what's called seasonal affective disorder. The protocol I just described is exactly the same protocol that they have used successfully to offset seasonal depression.

• 40:43Andrew D. Huberman?

  Now, I realize that most of you listening to this don't live in areas of the world too close to the poles. So no doubt, you get more sunlight available to you during the winter than you do if you were to, say, live in Scandinavia or down at the South Pole. However, these days, most people are not taking advantage of those early hours of the day to get outside and get bright light from sunlight or from a 10,000 lux artificial source. In fact, most people just look at their phone or flip on a few indoor artificial lights, and that is not going to be sufficient to boost your cortisol levels the way you need to in order to achieve the kind of elevation in mood focus and alertness, and that can offset things like not just seasonal depression, but mild depression, malaise, lack of daytime energy, and on and on.

• 41:28Andrew D. Huberman?

  So this thing about viewing bright light early in the morning, it's a real thing from the standpoint of the mechanism is understood, the ideal timing is understood, the magnitude of the impact on cortisol is very significant, these are big effects, and it's clinically significant with respect to mood, meaning you're going to feel more energized, you're going to feel better. Okay, so now that you understand that getting your cortisol high upon waking is the right thing to do, this is what you want, let's talk about some of the other things you can do besides viewing bright light in order to increase your morning cortisol. But keep in the back of your mind that viewing bright light is the foundation. Okay, so you wake up in the morning, and as quickly as you can, you get bright light into your eyes. What else should you do to boost your cortisol?

• 42:13Andrew D. Huberman?

  Well, there are a number of things that you can do and that you should do every single day. Most of them are pretty easy, and many of them can be combined. One of those is hydration. Now, of all the protocols in the realm of mental health, physical health, and performance, I think the most underrated one, believe it or not, is hydration. When you look at the literature on hydration and the effects of even mild dehydration, what you find is that cognitive function, physical function, basically cellular function and organ function generally, all suffer when you're even mildly dehydrated. So it's very important that you hydrate first thing in the morning. For me, that's 16 to 32 ounces of water with some electrolytes in it, for you, it might just be water, whatever. The interesting thing is that one of the major effects of proper hydration is to increase

• 42:54Andrew D. Huberman?

  levels of alertness, and the way it does it is by acting on the adrenals, both epinephrine, adrenaline, and cortisol release. And we're not talking about big spikes in cortisol related to drinking water, we're talking about modest increases in the levels of pulsatile, as it's called, release of cortisol due to hydration. So hydrating first thing in the morning, also a terrific idea. You can do this while you get your bright light outside, or while you get your bright light from a 10,000 lux artificial source. Hydrate first thing in the morning. It's going to increase your levels of energy then and throughout the morning and into the afternoon. Again, highly underrated protocol in part because it takes a lot, a lot of dehydration before we realize that we're dehydrated. When you wake up in the morning, you use the restroom, you're probably mildly dehydrated.

• 43:39Andrew D. Huberman?

  Get yourself hydrated first thing in the morning. Your cortisol levels will thank you, your levels of energy will thank you. Now, if you're like me, you also hydrate with caffeine. Okay. Now, the discussion around caffeine and cortisol can be a little bit confused by the sort of discrepancies in the literature as to, yes, caffeine increases cortisol, or some studies that show, no, caffeine doesn't increase cortisol, but it might extend the life of cortisol. Here's the big picture on caffeine and cortisol, at least the meaningful one. If you're a chronic caffeine user, meaning you drink caffeine every day, or you've consumed caffeine every day for the previous five days, which is the typical framework in one of these studies, and then you drink caffeine, 100 milligrams, 200 milligrams, 300 milligrams,

• 44:21Andrew D. Huberman?

  even an energy drink that includes caffeine and some other things, the increase in cortisol that you're going to experience is probably not that significant, unless it's a massively elevated dose of caffeine for you. However, if you're somebody who's not caffeine adapted, you're not drinking caffeine every day, you haven't had it for the last five days, then yes, you will experience a significant increase in cortisol levels. So you have to ask yourself, are you a chronic caffeine user? Are you an occasional caffeine user? Or do you not use caffeine? If you're somebody who avoids caffeine because it makes you anxious, or you just don't like it, then by all means, don't drink caffeine just to spike your cortisol. It will be very effective in spiking your cortisol, but I can't really encourage you to drink caffeine if you don't want to.

• 45:03Andrew D. Huberman?

  If however, you're somebody who regularly drinks caffeine, you now know that it's not going to boost your cortisol levels that much, maybe a little bit, depending on how much you drink. If it's a typical amount for you, meaning you're caffeine adapted to that amount of caffeine, probably not much cortisol increase will come from drinking that amount. However, it will prolong the duration of cortisol's effectiveness in your bloodstream. And this has to do with a number of different pathways. But the point being, if you have your caffeine, say, 30 minutes after waking, or five minutes after waking, or 90 minutes after waking, well, it's probably not going to boost your cortisol levels that much if you're already viewing bright sunlight, you're hydrating. We'll talk about exercise and some other things in a moment.

• 45:46Andrew D. Huberman?

  But if you're drinking that caffeine shortly after waking up, or shortly close to when you get that big cortisol spike, it's going to make the downslope of that cortisol spike a bit more gradual. Or if you're drinking caffeine throughout the morning, a lot more gradual. So let me present two scenarios in which you can use caffeine to improve your levels of move, focus, and alertness by way of the cortisol pathway. And here, I'm only speaking to people who habitually use caffeine. So you're drinking caffeine every morning. The first group is one that I commonly encounter. These are people that say, listen, I don't care what I hear out there. I want my coffee, or I want my yerba mate, which is my preferred source of caffeine, first thing in the morning. Ideally, even before water. Well, there, I'd say, please drink water first. But even if you're not going to, sure, go ahead and drink your caffeine.

• 46:31Andrew D. Huberman?

  Drink that caffeine. It's not going to boost your cortisol that much. But make sure you're doing a bunch of other things. Bright light viewing, talk about exercise in a moment, et cetera. Do a bunch of other things to make sure that morning cortisol spike is really, really high, because that's what you want. Now, there's a second group of people that say, hey, I want my caffeine first thing in the morning, or I'm drinking my caffeine first thing in the morning. But then I'm crashing really hard in the late morning, crashing really hard in the afternoon, and it's not because I'm not sleeping well at night. Like, something's happening. This is where the recommendation that I've been making for some years now of delaying your caffeine by anywhere from 60 to 90 minutes comes about. You now know that caffeine, for a habitual user,

• 47:16Andrew D. Huberman?

  is not going to increase your cortisol levels that much. However, you also now know that drinking caffeine will extend the life of cortisol somewhat. So the logic here is, if you drink your caffeine not immediately after waking, but let's say, an hour after waking, or 90 minutes after waking, it's going to flatten out a bit the downslope of that cortisol as you transition from late morning into the early afternoon. A lot of reason why people crash in the afternoon. They get that extreme fatigue typically after lunch. Yes, it can be due to eating too much at lunch. Yes, it can be due to eating too many starchy carbohydrates or sugars at lunch.

• 47:58Andrew D. Huberman?

  It can be due to lack of sleep, but assuming that you're doing all the things right and you're still experiencing that crash in the afternoon. There's a good chance that it's because your morning cortisol peak, high enough or no, is coming down too fast. And in order to make it more gradual, you simply shift your caffeine intake a little bit later so that that diminishing caffeine level that it starts to occur around 10 a.m., 11 a.m. Of course, all of this relates to exactly when you wake up. But that dropping level in caffeine isn't a steep cliff. It's a little bit more gradual. And I can't tell you how many thousands of people have contacted me and said, "Oh, my goodness, I can't believe it." Simply by pushing out my caffeine intake by 60 minutes or even 30 minutes, or in some cases, 90 minutes after waking,

• 48:41Andrew D. Huberman?

  I've been able to not experience that crash in energy in the afternoon. And they generally thank me for this. Indeed, most all of them are writing to me to thank me for this. For those of you that absolutely love your caffeine first thing in the morning, you want your caffeine first thing in the morning and you just refuse to delay it, fine. I never, ever said that you couldn't do that. In fact, you can do whatever you want. I'm simply giving you an opportunity to extend the life of that morning cortisol pulse. Caffeine's a great way to do that. And for those of you that don't consume caffeine regularly, but like to use it as an occasional tool, like if you need to stay up late, for instance, or, you know, only under conditions in which you really, really need to wake up quickly. Well, in that case, it's actually going to be a pretty terrific tool because you will indeed achieve a big increase in cortisol energy and alertness,

• 49:26Andrew D. Huberman?

  which for the rest of us habitual caffeine users, where you're seeking every day, we're drinking our caffeine and it's harder and harder to get. That's just the nature of caffeine tolerance. Okay, let's talk about exercise and its effects on cortisol. In many ways, exercise's effects on cortisol are similar to those of caffeine. And I say that because it really depends on how regularly you perform a particular type of exercise. Now, studies of the effects of exercise on cortisol are complicated by the fact that sometimes they looked at people who are regular exercisers. Let's say they were runners, they look at the effects of running on cortisol. Or they were resistance trainers. Okay, so they do weightlifting. And then they look at the effects of weightlifting on cortisol.

• 50:09Andrew D. Huberman?

  They look before, during, and after, this kind of thing. They look at the function of frequency of training. All of that's been done. However, some labs have also explored the effects of, say, runners who take up resistance training, or people who are non-exercisers who suddenly start resistance training or running. When I looked at all of that literature, you come away with a picture where, just like with caffeine, if you are accustomed to exercising in a particular way and at a particular time of day, the elevation in cortisol that you experience from that workout is going to be less than if it's a completely novel scenario, both in terms of time and the type of workout. In other words, if you're like me and you like to exercise within the first three hours

• 50:52Andrew D. Huberman?

  of the day, and you exercise in the first three hours of the day doing either resistance training or cardiovascular exercise, because I'll do both on separate days, but I'll do both, neither of those is particularly novel to me, and I do those at the intensity that is familiar to me, which for me is moderate to high intensity, well, the increase in cortisol that one experiences is not that great. You get big increases in other things like the catecholamines, dopamine, epinephrine, and norepinephrine, and yes, you do get some increase in cortisol. In particular, in the late stages, meaning late in the first hour of exercise, typically my resistance training sessions don't span longer than 90 minutes. That includes the warm-up and the cool-down. So after about 70 minutes of resistance training with real effort, close to failure

• 51:36Andrew D. Huberman?

  or to failure, you know, this kind of thing, cortisol levels are way up, and they'll stay up for a short while, meaning an hour or so after exercise, and then they'll come back down, especially if you're doing things to deliberately bring them down, including eating a meal laden with carbohydrates, which will help bring those cortisol levels down. But if, for instance, somebody who's never resistance trained, or who's primarily an endurance athlete, starts resistance training in that way, the literature points to the fact that they will experience much higher cortisol levels, and those cortisol levels will be sustained over many more hours. The same thing could be said for endurance exercise or for high intensity interval training. I don't want to complicate things too much by spelling out each of the different scenarios.

• 52:19Andrew D. Huberman?

  I will provide a link to it, what I consider a really nice paper. It's just one of the several pointing to this, but the title of the paper is endocrine responses of the stress system to different types of exercise. And they looked at single bout endurance, regular endurance, single bout, high intensity exercise, regular high intensity exercise, single bout resistance, regular resistance. So they went through not all, but many of the permutations that are possible and spell out what are the effects on cortisol? What are the effects on the catecholamines, norepinephrine and epinephrine in this case? What are the effects on inflammatory cytokines? We sometimes forget this, but inflammatory cytokines are a healthy byproduct of exercise because those trigger the adaptations in your immune system and other tissues to adapt,

• 53:04Andrew D. Huberman?

  to get stronger, including your immune system. And they also looked at growth hormone. It was kind of interesting because where you find big increases in cortisol, you also see big increases in growth hormone in response to exercise, meaning when the exercise is novel, either because it's a new form of exercise or because the intensity is novel. So we can take a step back and say with certainty, exercise increases cortisol. However, if the form of exercise and the timing is very familiar to you, the amount of cortisol and in particular, the duration of cortisol increase is not going to be that significant as compared to if it's a completely novel form or timing of exercise. Now, is the increase in cortisol that's achieved with your, let's call them your regular workouts, right?

• 53:47Andrew D. Huberman?

  Typically if you run or you lift weights or you do some sort of interval training, if you're doing any number or just one of those things, is the amount of cortisol increase that you experience going to be significant in terms of helping you anchor that cortisol cycle so that cortisol is higher in the morning and lower in the afternoon and evening? The answer is yes. Exercise of a type that's familiar to you, of an intensity that's familiar to you, may not significantly increase your cortisol levels as compared to a form of exercise that's completely novel. However, exercise provides a very strong, what's called entrainment. Entrainment cues are cues of things that we do. These could be meals, it could be light exposure, it could be exercise. It could be all sorts of things, even social engagement,

• 54:31Andrew D. Huberman?

  that feed back onto the SCN, the suprachiasmatic nucleus, and reinforce the timing of the cortisol release that the SCN causes. So there are these beautiful interactions between exercise, the SCN, and cortisol release, that when we exercise at roughly the same period of time each day, doesn't have to be right on the minute, but within the same two or three hour window each day. And since, like most people, you're probably not exercising every single day, perhaps three days a week, four days a week, ideally five or six days a week. When you do that, pretty soon, you get a cortisol increase simply in response to the timing rolling around in a very Pavlovian way, even if you don't exercise. Now, you have to keep exercising to maintain that.

• 55:13Andrew D. Huberman?

  But the key here is that when you exercise in the same two to three hour window each day, or at least three days a week, ideally four, five, six days per week. I do think it's important to have at least one complete rest day. When you do that, that big peak in cortisol that's endogenously generated by your SCN, that's just internally generated without doing anything else, it gets anchored to that stage of the day in a very solid way as compared to people who don't exercise early in the day. So the point here is that you exercise, sure, to increase your cortisol, but probably for a bunch of other reasons, more than you do to increase your cortisol. But getting your cortisol rhythm correct is absolutely essential.

• 55:56Andrew D. Huberman?

  In fact, it's going to give you the anticipatory energy for exercise. In fact, you can try this, it's remarkable. If you exercise at the same time of day for, say, four to five, maybe six days per week, you just do that for a week. And it doesn't have to be, again, exactly at the same time you start, exactly the same time you stop, plus or minus 30 minutes. What you'll find is that in the hour leading into that exercise, you will start to experience an increase in energy and it's not just psychological. There's an anticipatory rise in cortisol that's governed by the SCN and this process that we call entrainment, which is anticipation. It's kind of like a Pavlovian response, but it's on a longer timescale. Well, regardless of timescale, it's a very real thing.

• 56:38Andrew D. Huberman?

  So if you're somebody who doesn't seem to have much energy, much get up and go in the morning, and you're getting your bright light, you're getting your hydration, maybe you're even drinking caffeine, you're doing all of that, and you're still feeling kind of sluggish, exercising for three or four days, not necessarily in a row, feel free to introduce a rest day as needed, but doing that across the course of a week for four to six days will lead you into a second week, a third week, etc., provided you keep it up, where you're going to have more energy heading into the exercise, therefore more energy to exercise. It's just going to be a positive feedback loop on your cortisol levels. This is a very robust effect, and in fact, it's so robust that you can observe it in mice, you can observe it in dogs. Your dog knows when it's time for a walk, even if you don't say walk.

• 57:22Andrew D. Huberman?

  It has internal endogenous cues that, you know, between the hours of whatever, seven and nine AM, it's time for a walk, and it will start to experience a surge in energy. You are the exact same way. These are hardwired, very long-established systems in our brain and body, and you can absolutely give yourself more energy to do the things that require energy by exercising at roughly the same time. Again, within the same three-hour window is probably the broadest, but you know, even better would be in the same two-hour window each day. And if you miss a day, no big deal. You'll just have more energy during that time to devote to other things. Okay, what about deliberate cold exposure? Cold showers, cold plunges, this kind of thing. You all know that deliberate cold exposure wakes you up.

• 58:06Andrew D. Huberman?

  Okay? Despite it being somewhat controversial in other domains like metabolism, deliberate cold exposure definitely wakes you up, and it wakes you up very fast. And it does that because it causes the release of epinephrine and norepinephrine. And then you get this long arc of dopamine release. This is one of the major reasons, if not the major reason, why people who start deliberate cold exposure continue to do it, right? If for no other reason, it wakes people up, makes them feel good for many hours afterwards. Now, I know many people are averse to the cold, they really don't like it, and frankly, if you don't like it, you don't have to do it. But it absolutely causes an increase in the catecholamines, dopamine, epinephrine, and norepinephrine, and the long-lasting effects on dopamine are quite striking.

• 58:49Andrew D. Huberman?

  Meaning, there are very few other things that can cause that long, slow release of dopamine to the levels that it does, which changes mood, alertness, et cetera, for many hours after. Now, the big question for sake of this discussion is, does deliberate cold exposure cause the release of cortisol? And just like with exercise, just like with caffeine, the real question that we have to ask ourselves is, how novel, how unfamiliar is that deliberate cold exposure? Because while the perfect experiment has never really been done, if you amass the literature on this, what you find is that if you put people into very cold water, or even just cold for them, uncomfortably cold for them, water, yes, they'll increase more cortisol. Yes, they'll release cortisol into their bloodstream.

• 59:34Andrew D. Huberman?

  However, if they do this habitually, then the increases in cortisol are not meaningful. They're not statistically significant. So that actually leads to two important takeaways. The first one is, if you want to use deliberate cold exposure as a way to increase cortisol, great, do that, but probably don't do it more than, say, one or two times per week. Otherwise, it will lose its effectiveness for that purpose. It will still be very effective for all the other reasons that deliberate cold exposure has been purported to be effective, including increased release of catecholamines. So the takeaway here is very straightforward. If you want to boost your cortisol levels using deliberate cold exposure, cold shower, ice plunge, whatever it is, you can do that. But it needs to be occasional deliberate cold exposure, probably not more than twice per week.

• 1:00:18Andrew D. Huberman?

  Otherwise, you're not going to get a significant increase in cortisol as a consequence of that deliberate cold exposure. However, if you're somebody who likes doing deliberate cold exposure, keep in mind that it's not going to chronically elevate your cortisol. This is advantageous for a number of reasons. First of all, it will, yes, continue to elevate your levels of dopamine, norepinephrine, and epinephrine for increased mood and energy. That effect persists. As far as we know, that effect never saturates. But if you're somebody who's concerned about elevating your cortisol too much, you're concerned about chronic elevation of cortisol. And I hear a lot about this in the circles around, you know, important differences between men's fitness and health and women's fitness and health.

• 1:01:01Andrew D. Huberman?

  And maybe that deliberate cold exposure is good for men and not for women. There's really no evidence to support that. In fact, the evidence points in exactly the opposite direction, which is that when people, men or women, do deliberate cold exposure regularly, more than twice per week, then the impact on cortisol is not significant. And yet, they still can benefit by getting those increases in dopamine, epinephrine and norepinephrine. I'd like to take a quick break and acknowledge one of our sponsors, Element. Element is an electrolyte drink that has everything you need and nothing you don't. That means the electrolytes, sodium, magnesium and potassium in the correct amounts, but no sugar. Proper hydration is critical for optimal brain and body function. Even a slight degree of dehydration can diminish cognitive and physical performance.

• 1:01:44Andrew D. Huberman?

  It's also important that you get adequate electrolytes. The electrolytes, sodium, magnesium and potassium, are vital for functioning of all the cells in your body, especially your neurons or your nerve cells. Drinking Element dissolved in water makes it very easy to ensure that you're getting adequate hydration and adequate electrolytes. To make sure that I'm getting proper amounts of hydration and electrolytes, I dissolve one packet of Element in about 16 to 32 ounces of water when I first wake up in the morning. And I drink that basically first thing in the morning. I'll also drink Element dissolved in water during any kind of physical exercise that I'm doing, especially on hot days when I'm sweating a lot and losing water and electrolytes. Element has a bunch of great tasting flavors. I love the raspberry, I love the citrus flavor. Right now, Element has a limited edition lemonade flavor that is absolutely delicious.

• 1:02:29Andrew D. Huberman?

  I hate to say that I love one more than all the others, but this lemonade flavor is right up there with my favorite other one, which is raspberry or watermelon. Again, I can't pick just one flavor, I love them all. If you'd like to try Element, you can go to drinklmnt.com/huberman, spelled drink L M N T dot com slash huberman to claim a free Element sample pack with a purchase of any Element drink mix. Again, that's drinklmnt.com/huberman to claim a free sample pack. Okay, let's talk about some of the other things that you can do to increase your morning cortisol levels. If you're starting to get the picture that cortisol is something that you want high early in the day, And that you want tapering off later into the day? Great, then you're getting the picture correctly. In fact, one way to think about it is that cortisol is kind of like a wave that starts on its

• 1:03:14Andrew D. Huberman?

  own, but for which you can increase the height of that wave and catch that wave early in the day and into the afternoon. If you imagine it that way, then you're probably saying, what other things can I do besides viewing light, besides hydration, besides caffeine, besides exercise? And probably part of the reason you're asking is that not all of us are able to do all of those things every single day. I do acknowledge that. So the larger the toolkit of things that you can use to increase your morning cortisol peak, the more flexibility you have when trying to come up with those, when traveling, when especially busy, and so on and so forth. So if we take a step back and ask ourselves what sorts of chemical compounds out there can help us increase our cortisol levels? We come up with some pretty interesting answers. And no, we're not going to talk about supplements.

• 1:03:59Andrew D. Huberman?

  It is true that certain supplements like yohimbine, like L-tyrosine, can have a modest effect in increasing cortisol, but we're not going to emphasize those. We're actually going to emphasize two naturally occurring foods that have a significant impact on cortisol levels. Both the amount of cortisol that you're capable of releasing early in the day and the duration for which that cortisol lasts. The first one is, of all things, grapefruit. Yes, grapefruit. Here I'm talking about the whole fruit, could be pink grapefruit, could be not pink grapefruit, yellow grapefruit, could be grapefruit juice. And before I get into the mechanism and the protocol, I should emphasize that the effects of grapefruit on cortisol are not trivial, they're significant. So if you eat a grapefruit, or you drink a, I don't know, six to eight ounces of grapefruit

• 1:04:44Andrew D. Huberman?

  juice, it's going to have a meaningful impact on how long the cortisol that's already in your bloodstream lasts. The way it does that is grapefruit contains compounds that inhibit the enzymes that break down cortisol. In particular, compounds in grapefruit inhibit the action of an enzyme called CYP3A4 and maybe A5 as well. And that enzyme is responsible in large part for breaking down cortisol. It's not the only way that cortisol is broken down, but it's one of the major ways. And grapefruit has a significant impact in inhibiting the enzyme that breaks down cortisol. So believe it or not, many studies have been done in humans, men and women. And the net takeaway is the same in every case.

• 1:05:26Andrew D. Huberman?

  If you were to eat a grapefruit, you're going to extend the life of cortisol in your bloodstream by anywhere from 25 to 50%, right? That's significant, and it has actually been shown to be clinically significant. And the reason I say clinically significant in this case is that indeed, there are some people that need to deliberately elevate their cortisol using medication. Those people typically are instructed not to eat grapefruit or drink grapefruit juice because then they're not going to get as clear a picture on how a given dose of their medication is impacting their cortisol. Likewise, people who have chronically elevated cortisol are told not to eat grapefruit or drink grapefruit juice because it can further elevate their cortisol. However, most people who don't have things like Cushing's disease or Addison's don't

• 1:06:10Andrew D. Huberman?

  have to worry about this. And most people, probably you, are interested in having a lot more energy, get up and go early in the day, and you now know that elevating your morning cortisol is one way to do that. And many of you presumably don't always have time to exercise, or you don't always have time to get morning light. I know it sounds outrageous, but every once in a while, you can't get sunlight or bright light into your eyes. Well, you might be thinking about ways that you could increase your cortisol under those conditions. Well, eating a grapefruit would do that, or drinking some grapefruit juice. And of course, you can eat a grapefruit or drink some grapefruit juice in combination with all the other things that we've discussed. In fact, there are compounds in grapefruit juice that will also extend the effectiveness of caffeine.

• 1:06:51Andrew D. Huberman?

  So this effect of grapefruit on the various enzymes that break down things like caffeine and cortisol is a meaningful impact. It's not a trivial one. And so while it might seem kind of silly to say, oh, yeah, eat grapefruit to increase your morning energy, it's actually a real thing that's separable from the effects of grapefruit on, say, blood sugar that comes from the fructose in grapefruit, that comes from the vitamins and minerals and other things in grapefruit. There's a real and meaningful impact of grapefruit on the cortisol breakdown pathway. So if you're interested in boosting your morning cortisol, simply eat a grapefruit in the morning. I've started doing that late morning. I typically eat my first meal of the day somewhere around 10:30, 11:00 a.m. It sort of varies from day to day. I don't typically eat first thing upon waking. I do drink caffeine first thing upon waking if I'm going to exercise.

• 1:07:35Andrew D. Huberman?

  Most other days I delay my caffeine a bit. In any case, in the last few weeks, as I've been researching this episode, I've started consuming one pink grapefruit, which I personally find delicious, late morning before my first meal, and indeed I notice a tangible increase in energy, both late morning and into the early afternoon. Yes, perhaps some of that is placebo effect because I anticipated this effect of grapefruit. But the data and the literature and the mechanistic pathway is very clear. Grapefruit extends the life of cortisol. The other food that can increase cortisol is licorice. In particular, black licorice. We're not talking about red licorice, we're talking about black licorice. You might be thinking, what is this? Are we like getting into the realm of like really alternative medicine? No.

• 1:08:17Andrew D. Huberman?

  All you have to do is look at the list of things that people who are trying to reduce their cortisol, or who are taking medications to increase or decrease cortisol for a disease state, are told not to eat. And you get an insight into just how powerful licorice is, or I should say, things within licorice, are for increasing cortisol levels. What I'm talking about here is a compound called glycerin. Glycerin is in black licorice, and glycerin has been shown to have very big effects on increasing cortisol, so much so that if you are going to experiment with licorice, or glycerin that comes from licorice root, you need to actually be pretty careful to not boost your cortisol levels too much.

• 1:09:01Andrew D. Huberman?

  Start with the lowest possible dose of licorice root, if you're going to use it in capsule form, if you're going to eat black licorice. A lot of people like black licorice, a lot of people are averse to black licorice, it's kind of a individual thing. If you're going to do that, you're going to need to be cautious about not spiking your cortisol too much, especially if you're eating it later in the day. We're not to late day cortisol control just yet, but licorice significantly boosts your cortisol levels, and it does so by inhibiting the enzyme 11 beta hydroxy steroid dehydrogenase, or 11 beta HSD for short.

• 1:09:36Andrew D. Huberman?

  This is the enzyme that's involved in the conversion of cortisol to cortisone. So cortisol, when released into the blood, eventually is broken down into a bunch of other things. And in order to keep the cortisol active, and here we didn't get into a discussion about cortisol either being bound or free, okay? The free form is the one that's active and can impact tissues, just like free testosterone can impact tissues as opposed to bound testosterone. Because it's also a steroid hormone, cortisol goes through some of the same regulation. The important point here is that licorice can be used to potently increase cortisol, not just the duration of cortisol's impact, but also apparently the release of cortisol. Now, the data on that are a little bit mixed.

• 1:10:19Andrew D. Huberman?

  Some people would even argue that licorice can increase the synthesis of cortisol, but there, there's even less data. The data are very clear, however, that glycerin, which is prominently found in black licorice, you are going to increase the amount of cortisol circulating in your bloodstream. So if you're having a really difficult time boosting your cortisol in the morning, despite doing all the other things that I'm describing, or let's just say there's a day in which you can't exercise, you don't have access to bright light, you can't do all the things that you would need to in order to boost cortisol, but you want to, maybe that's the day that you try a small amount of licorice root, or a small amount of black licorice. One very important point, licorice has a potent enough effect on cortisol, and cortisol

• 1:11:03Andrew D. Huberman?

  has a potent enough effect on blood pressure that if you suffer from hypertension or high blood pressure, or if you are pregnant or breastfeeding, you absolutely do not want to eat black licorice. I don't know whether or not this is commonly told to women who are pregnant or breastfeeding, but when I looked in the literature, this was a repeated theme. Women who are pregnant or breastfeeding, people with elevated blood pressures should not be consuming black licorice. The glycerin is potentially hazardous for them, or the fetus. So I say that in part to inform you about licorice and its effects on cortisol, but also that you be mindful that licorice has a potent effect on the cortisol pathways. Okay, so we've talked about how to control your cortisol in the morning for more energy, focus, alertness, et cetera, all day long.

• 1:11:46Andrew D. Huberman?

  However, your endogenous rhythm of cortisol dictates, right? You don't have control over this. It dictates that your cortisol is going to start to fall somewhere around noon, maybe 11 a.m., maybe noon, maybe 1 p.m. Remember, it all depends on when you woke up, because waking up is actually what triggers that big inflection in cortisol early in the day. But as your cortisol starts to fall into the early afternoon, late afternoon, and so on, you may notice something, which is you can experience stress. Sure, if you have a stress event, you'll get a spike in cortisol and it will come back down. But if you've ever been outside during the middle of the day, got some sunlight in your eyes, maybe sitting with your eyes closed, maybe even relaxing in the sun, you'd probably say,

• 1:12:29Andrew D. Huberman?

  getting bright light in my eyes, getting sunlight in the afternoon, keeps me calm. If anything, it makes me mellower. It doesn't tend to wake me up. But remember, it was only in the first hour or so after waking up in the morning, that bright light causes this big inflection in your cortisol and contributes to more energy. In the afternoon, that system is gated, it's shut down. This is what's referred to as the circadian dead zone in circadian biology. You can't actually shift your biological clock with light at that time, which doesn't mean that getting sunlight on your skin or in your eyes isn't a good thing. It indeed is a good thing. Of course, you want to guard yourself against too much UV exposure by wearing clothing, or perhaps a mineral-based sunscreen, etc.

• 1:13:12Andrew D. Huberman?

  But getting sunlight in the middle of the day can be a terrific thing for your mood. There are great studies showing that it can enhance hormone production, including testosterone and estrogen, feelings of well-being. But indeed, getting sunlight and other forms of bright light in your eyes and on your skin in the afternoon, tends to make you feel kind of relaxed. And that's because that positive feedback loop that the SCN can trigger, whereby light increases your cortisol, is completely shut down from the hours of about noon time or so, until about five or six in the evening. Now, I say until about five or six in the evening, because in the evening, cortisol is going even lower, lower, lower, but then something happens. The gate, the opportunity for light to start

• 1:13:56Andrew D. Huberman?

  triggering increases in cortisol, opens. And as you'll soon learn, not only does it open, but it's extra sensitive. Put differently, in the evening, past sundown, so this will be different, different times of year, different locations on earth, but About two hours after sundown or so, any bright light from an artificial source, especially short wavelength light of the type that comes from LEDs and computer screens and phones, that sort of thing, can cause big increases in cortisol. And that, of course, provides a perfect segue for us to talk about the things that you should do in the evening and at night to make sure that your cortisol is low and dropping further still. Okay, so let's talk about the things to do in the evening and at night in order to quote unquote, optimize your cortisol levels.

• 1:14:41Andrew D. Huberman?

  And when I say optimize, of course, there's no optimal exact level. There's no optimal level for one exact time. Everyone's on slightly different schedules. I tend to go to sleep somewhere between 10:00 PM and midnight most nights. Sometimes it's 9:30. Sometimes I'll stay up past midnight. It happens every once in a while. You may go to bed at 8:00. You may go to bed at 1:00 AM. The point here is that we're focused now on the portion of your endogenous, naturally generated cortisol rhythm that occurs in the hours before bedtime, when your goal is to get to sleep and get terrific sleep. And what that requires is that your cortisol is low and continuing to go lower. So there are various things that you should do in the afternoon and evening and nighttime to make sure that pattern occurs.

• 1:15:25Andrew D. Huberman?

  The first task to do with lighting. As I just described, in the evening, about two hours after sundown is really when this phase of your cortisol cycle begins, where not much light is required in order to create big increases in cortisol, which is the exact opposite of what you want in the evening and at night. You want your cortisol going down, not up. So how do you control your lighting in order to ensure that pattern occurs? There are several ways. First of all, you just dim the indoor lights, dim them as much as possible, especially overhead lights. The neurons in your eye that send information about overall luminance, how bright it is in your environment, they're all over your eye, but they reside primarily in the lower two thirds of your eyes, because their role is to view

• 1:16:10Andrew D. Huberman?

  the upper visual field. And that's how that circuit is arranged. So if you have to have lights on in your indoor environment at night, which most people do, you should dim as many lights as you can, turn off as many overhead lights as you can. Table lamps are better than overhead lights and floor lights are better than table lamps. Most people aren't going to install floor lights. But if you find that you're having trouble mellowing out and getting to sleep, and there isn't some other reason for that, like you drank a bunch of caffeine at 8:00 PM or 6:00 PM, then... Dimming the lights is going to be a terrific idea. Now, the wavelength, the color of those lights can also have a big impact. As I mentioned before, you want to avoid short wavelength light exposure. So this would be your white LED lights, blue lights, green lights.

• 1:16:54Andrew D. Huberman?

  If you can, all right, and there are various ways you can do this. You could purchase a red light bulb. I'm not talking about red light therapy, but there are various sources of red lights that you can install. They're very inexpensive. Again, it's not red light therapy. It's just restricted such that I'm only getting long wavelength light in my eyes. Why? Well, there are a number of papers showing that if we restrict our visual exposure to medium and long wavelength light in the evenings and at night, it does not have nearly as much impact on increasing cortisol. Now, if it's very, very bright, we're talking like bursting bright red lights, it can increase cortisol even in the evening. But if it's relatively bright to dim red light or amber colored light of the sort that you would get with an incandescent bulb

• 1:17:37Andrew D. Huberman?

  as opposed to an LED bulb, that's going to keep cortisol low. And the effect of these lighting changes is not trivial. These are meaningful protocols that will actually help keep your cortisol low, help keep you calm and mellow. And of course, you should dim the screen on your phone and your computer. There's actually a way, if you have an Apple phone, that you can very easily program in a triple click shortcut so that your screen turns red. We can provide an instruction of how to do that in the show note captions. It takes about two minutes to do. I have this on all my phone devices, so it can triple click on the side and then it brings your phone screen from its standard luminance to basically a red screen. So it cuts out all the short wavelength light. And of course, if you're interested in using glasses that restrict short wavelength light,

• 1:18:21Andrew D. Huberman?

  as some of you probably know, I worked in collaboration with Roka Glasses to develop what we call the wind down glasses. They're not just blue blockers. They don't just cut out the Blue wavelengths of the visual spectrum, they cut out all the short wavelength light that can stimulate the cells that can increase cortisol and so on and so forth. So the glasses are convenient because oftentimes you don't have control over your indoor lighting environment, right? If you're out to dinner or you're in a hotel, you didn't bring a red light bulb, this kind of thing. You go into the bathroom, you know, what are you going to do there if the red light bulb is in the bedroom and this kind of thing? So you could use those, you could use a red light bulb, certainly dim all the lights that you can. This makes a meaningful and powerful contribution to keeping your cortisol levels low. It will also prevent you from reducing levels of melatonin, which is the hormone that makes you sleepy at night.

• 1:19:06Andrew D. Huberman?

  So as cortisol is going down, melatonin is going up in the evening and at night, and that's what you want. You want cortisol as low as possible, you want melatonin as high as possible. Keep in mind that bright light, especially short wavelength bright light, so blues, greens, et cetera, the type that comes from white light from screens, unless you do something to alter that light, is going to be a potent stimulus for increasing cortisol and for decreasing melatonin. And here I should remind you that you know exactly why even moderately bright light, that short wavelength light in the evening is so effective at increasing cortisol. Because cortisol levels are so low, that negative feedback loop, right? Your hypothalamus is registering the levels of cortisol in your system in the evening,

• 1:19:51Andrew D. Huberman?

  and they're very, very low. So it is primed to make more cortisol if it needs to. This again is an ancient mechanism by which your brain has learned how to control levels of cortisol in your bloodstream so that they're never too high or too low. And presumably this creates an adaptive advantage whereby, you know, if you got into some sort of trouble in the evening and needed to escape a predator or whatever, maybe you need to stay up all night in order to search for food because food had been scarce in the previous days, you could do that, right? Your cortisol levels are very low and you can stimulate them to increase very easily. Put differently, It's very easy to stress at night. It's very easy to create increases in cortisol because your endogenous, your circadian levels of cortisol are so low.

• 1:20:32Andrew D. Huberman?

  So you have to be very careful not to trigger yourself to not create these inflections in cortisol. If you're somebody who's noticed that in the evening, you tend to be a bit more reactive, that things that you see online or different conversations you might have by text or thoughts within your head tend to make you more anxious later in the day. Well, that's probably because you're experiencing these sharp inflections in cortisol relative to your already low, appropriately low, I should say, levels of baseline cortisol at those times of evening and night. There are a few other things you should do to keep your cortisol low. And then I'll talk about some of the things that you can do to proactively keep your cortisol low, meaning the to do's, not just the don'ts. A couple of other do nots are things like ingesting caffeine. This is kind of an obvious one, right?

• 1:21:13Andrew D. Huberman?

  I tend to drink a lot of caffeine early in the day for reasons you now understand. You may drink your caffeine early in the day as well, perhaps in the early afternoon. If you're having trouble falling and staying asleep throughout the night, maybe just waking up once in the middle of the night to use the bathroom, which is fine. But if you're finding that you're waking up multiple times during the night or you're not waking up feeling fully rested, you should really explore how late in the day you're continuing to consume caffeine. I recommend a cutoff of about 2:00 PM. Now, I'm very caffeine tolerant, so for some people noon might be the cutoff. For other people, 4:00 PM might be that cutoff. But in general, because most people go to sleep sometime between 9:30 PM and 11:30 PM, it's a good idea to cut your caffeine intake off somewhere around 2:30 or 3:00 PM

• 1:21:56Andrew D. Huberman?

  at the very latest so that you can fall and stay asleep easily. Remember, caffeine is not necessarily increasing your cortisol that much if you're a chronic caffeine user, but it's extending the life of cortisol so that that cortisol curve, that level of cortisol in your bloodstream is going to come down more slowly if you're drinking caffeine in the late afternoon. The other one is, of course, to limit your stress. Now, I've done entire episodes about stress and stress is a multifaceted thing. We can't always limit our stress. Life, I should say, even a good life, includes stress, short-term stress, long-term stress. And we'll talk more about chronic, long-term stress in a little bit. We're certainly going to talk about burnout and the different types of burnout that can result from different kinds of stress. But here's the key point about limiting your stress.

• 1:22:40Andrew D. Huberman?

  The best things you can do for stress involve controlling your stress response in real time. Okay, I'm a big fan of meditation. I'm a big fan of getting great sleep every night. I'm a big fan of vacations. However, when stress hits, we don't often have the opportunity to take a vacation, get a massage, do meditation. If you do, great, but most people don't have that level of control over their life in the moment. So having tools that you can deploy to deal with stress in real time and bring your levels of what we call sympathetic autonomic nervous system activity, which is just nerd speak for stress, down, is going to be very useful. And the best tool that I'm aware of, that's backed by terrific science, not just from my lab, I have been involved in some of the science, but from other laboratories as well.

• 1:23:23Andrew D. Huberman?

  And the body of research on this is ever-expanding. And it all points in the same direction, which is that exhale emphasized breathing slows your heart rate down through a process called respiratory sinus arrhythmia. And exhale emphasized breathing engages the diaphragm, which helps balance levels of carbon dioxide and oxygen in your bloodstream and brain in ways that bring your levels of stress down all very quickly. In fact, and I know some of you have heard this before, the fastest way to calm down in real time is going to be the so-called physiological sigh, which is just a big, deep inhale through your nose, then a second sharp inhale to try and maximally inflate your lungs, and then a long exhale until your lungs are empty. And that long exhale should be done through your mouth.

• 1:24:08Andrew D. Huberman?

  Even though I've demonstrated this many times before, I'm going to demonstrate it again for those of you that haven't seen it. It goes like this.

• 1:24:27Andrew D. Huberman?

  All right, I can feel my heart rate go down. You can probably even just hear it in my voice. The timbre of the voice and your levels of autonomic activation are very closely linked. We all know this because when people are really stressed, they sound stressed. And when they're relaxed, they sound more down here. Okay, it's really key that the first inhale be a big, long, deliberate inhale through your nose. It's really key that the second inhale be also through your nose, even though it's a sharp little inhale where you're not sneaking much air in. It causes maximal inflation of all the little sacs in your lungs. And then that allows you to maximally offload carbon dioxide when you do that long to lungs empty exhale. The whole thing, as you just saw, probably takes about 30, 40 seconds, maybe a minute maximum.

• 1:25:11Andrew D. Huberman?

  And it is the fastest and most effective way to calm yourself down in real time. So if you're experiencing stress, especially in the evening and nighttime hours, do one to three physiological sighs. If you can't remember to do that because you're so stressed, just do some emphasized exhale breathing. Just, just think about dumping your air through your mouth until your lungs are empty. And then do a physiological sigh or two. I can't overemphasize just how powerful this tool is. There have been now recordings of what's going on in the brain. People have looked at what's happening with carbon dioxide and oxygen ratios. Your heart rate slows down. There are a bunch of things that all contribute to shifting your autonomic nervous system

• 1:25:52Andrew D. Huberman?

  from a more sympathetic, activated mode to parasympathetic, so-called rest and digest mode. And it happens very, very quickly. So use breathing as a way to deal with stress in the evening. Again, it's a potent technique. And it's one that then puts you into the mental frame of being able to do the other things that you need to do in order to keep your cortisol low. Like make sure that the lights are dim, to make sure that you're not engaging in any kind of texting or online activity late at night that's going to further exacerbate your stress. The diabolical thing about stress is that when we are more stressed, when our sympathetic nervous system is activated, we tend to do more things that make us more stressed. This has to do with some of the adaptive nature of stress, why it's wired into us in the way that it is. But what I can tell you is if you can bring your levels of autonomic activation down,

• 1:26:37Andrew D. Huberman?

  calm yourself down. You have a lot more agency and control to direct your behavior and even to direct your thinking, the patterns of internal dialogue, and then you can navigate your nighttime and evening much more effectively, even if you are facing a night where you know you're gonna get less sleep, right? The thoughts about, oh, what would have then if I can't fall asleep and then tomorrow? All of that can be dealt with if you just bring your levels of autonomic activation down. So the breathing tool plus dimming the lights is going to be very effective for doing that. The other thing that you can do to bring your cortisol levels down in the evening and at nighttime is to consume some starchy carbohydrates. Now, I know I've talked a lot before about how most people should probably not eat for the two hours before they go to sleep, or ideally even the three hours before they go

• 1:27:22Andrew D. Huberman?

  to sleep. I'm gonna be real honest with you, I find it hard to fall asleep when I'm really hungry. So if it means having a small snack an hour or even 30 minutes before bed, I'll sometimes do that. But ideally, you're not eating anything for about two hours before you go to sleep. However, if you just have such gnawing hunger that you can't fall asleep, then you're going to have to eat something closer to bedtime, right? I think we should give ourselves permission to strike a balance between not having gnawing hunger that prevents us from sleeping, and also not eating too close to bedtime, which can impair the quality of your sleep. And indeed, it can also impair the release of growth hormone in the first hours of sleep. So what I recommend is eating in the evening and at nighttime. I usually eat dinner somewhere around, you know, ideally for me, it would be 6:30 to

• 1:28:07Andrew D. Huberman?

  8:30, somewhere in there. I'm flexible with these things, depending on my schedule, depending on the day. But if I'm going to eat dinner somewhere around 7:30 PM, I try to get some starchy carbohydrates in that meal. I tend to eat pretty moderate to low carb throughout the day. And then in the evening for my last meal, which again comes around 7:30 PM for me, 7:00 PM, I make sure that I have some starches. I have some rice, or I have some potatoes, or yams, or, you know, I like clean starches, so I tend to focus on those things, maybe some homemade pasta, whatever you're eating for starches. What you'll find is that eating starches in the evening will help keep your cortisol low. And guess what? It's absolutely obvious why that would be. Also, guess what? You know why. You know the mechanism.

• 1:28:52Andrew D. Huberman?

  Remember, cortisol's main job is not to deal with stress. It does that, but it's to deploy blood glucose so that you can deal, yes, with stress, but with all sorts of things in your schedule. Anything that requires energy and activity and certainly energy of the brain, but also energy of the body. So when you hear that there are quote-unquote comfort foods, those foods tend to be things that are very carbohydrate laden because those increase your blood glucose. And when your blood glucose levels are elevated, cortisol is not as readily released. I'm gonna say that again. When your blood glucose levels are elevated, your cortisol levels tend to stay low as well because it's not as readily released.

• 1:29:34Andrew D. Huberman?

  So there's a reason why people find that carbohydrates kind of calm them down, that they're comfort foods and that they relax them. It's because they don't directly suppress cortisol, but they act through the blood sugar regulation mechanisms that feed back to the hypothalamus to control release of cortisol. There are a couple of steps there in between, but think about it. The hypothalamus, this structure over the roof of your mouth that contains the neurons that can trigger the release of more cortisol or suppress its release, they're in a position, because remember, they're paraventricular and they have access to what's going on in the bloodstream to register levels of blood glucose. And so when blood glucose levels are elevated, and I'm not talking about extra high or, you know, pathologically high, I'm talking about, you know, after you have some pasta or you

• 1:30:16Andrew D. Huberman?

  have a bowl of rice or you have some oatmeal or whatever your favorite starchy carbohydrate is, the probability that you're going to release cortisol is going to be reduced. And the probability that you're going to continue to make cortisol at high levels is going to be reduced. So in the evening, or at least for your last meal of the day, having some starches, if that's within your nutritional plan, is a good idea if your goal is to keep cortisol low. And guess what? Your goal should be to keep cortisol low because you want to be relaxed in the evening and be able to sleep easily. Now, this opens up a broader conversation about what nutrition does in its different forms, high carb, low carb, et cetera, to cortisol. Here's a key takeaway, and I'm going to keep this very brief because in a future episode,

• 1:30:58Andrew D. Huberman?

  we could really go down the rabbit hole of how different diets impact different hormones, including cortisol. But the big takeaway here is they've done studies that explore low carbohydrate diets versus more typical carbohydrate diets. When I say low versus typical, the general contour of these across studies is something like this. What they call low carb means fewer than 30% of calories coming from carbohydrate. So here's the key takeaway. If somebody goes on a low carbohydrate diet and they've not been on a low carbohydrate diet, so fewer than 30% of daily calories from carbohydrates, maybe even lower. So it could be 5%, could be 20%, but relatively low carbohydrates. For the first three weeks that they're on that diet, you see a significant, it's not

• 1:31:41Andrew D. Huberman?

  an enormous, but you see a statistically significant increase in cortisol. And it matches the normal endogenous pattern that they already, which frankly, everybody expresses, which is higher in the morning, lower in the afternoon and evening. So it's not like the endogenous pattern is thrown off, it's just that curve has kind of shifted up a bit at various points, not every point. However, after about three weeks on that low carbohydrate diet, it normalizes, it comes back to their original level. Now, there's a lot of opportunity for speculation in there, like we could say, wait, after three weeks, the people on the low carb diet, their cortisol levels came back down, does that mean that their blood glucose levels went up? That doesn't appear to be the reason, there could be some other compensatory mechanisms. But the basic takeaway here is if you're on a low carbohydrate diet already and that's

• 1:32:25Andrew D. Huberman?

  working for you, you're able to sleep at night just fine. And I think that's probably the key thing that you should be asking yourself. If you're on a low carbohydrate diet, how's your sleep? If your sleep is great, terrific. If it's not, maybe you want to explore introducing some starchy carbohydrates to your last meal of the day, see how that goes. In any case, if you're on a low carbohydrate diet and you're sleeping fine, I wouldn't worry about its net impact on your cortisol. Because the studies I just described point to the fact that it's not chronically, long-term increasing your cortisol. If you're somebody who's moving from a higher carbohydrate diet to a lower carbohydrate diet, and you're noticing that you're, I don't know, feeling a bit more stressed, higher levels of sympathetic autonomic arousal, or feeling a little more activated,

• 1:33:09Andrew D. Huberman?

  keep in mind, if you're still in the first three weeks of that transition, that's to be expected. Your cortisol levels are shifted upward a bit. See how you feel in the fourth and fifth week, and then assess if it's right for you. Again, the relationship between starchy carbohydrates, glucose increases, and the relationship between cortisol being a mobilizer of glucose, makes it all very, very clear as to why there's this relationship between carbohydrate intake and cortisol. They're in a kind of a reciprocal relationship. Now, the one caveat to that is, indeed, if you are dealing with metabolic syndrome, like you are insulin insensitive, because you've been ingesting too many calories or too many carbohydrates, in particular, too many simple sugars, et cetera, all the things that can start to lead to insulin insensitivity, where you start cranking out more and more glucose,

• 1:33:54Andrew D. Huberman?

  because your insulin isn't doing such a good job of getting that glucose to your cells, what we call insulin insensitivity. Nowadays, people refer to it as metabolic syndrome, although that's a much bigger theme. Well, then, keep in mind that your cortisol levels will go up as you have less ability to use the glucose that you're making. And guess what? That makes perfect sense. Because as you can't use the glucose that you're making, it doesn't matter if your blood glucose levels are high, because that hypothalamus, it also needs to respond to glucose in an insulin-dependent way. It needs to actually be able to use those high levels of glucose. So again, the relationship between glucose and insulin sensitivity and cortisol, all jibes perfectly well when we think about mechanisms.

• 1:34:37Andrew D. Huberman?

  And the reason I'm going into all of this is so that you can have a thoughtful look at your nutrition. What are you eating? What percentage of it comes from starchy carbohydrates? How are those distributed across the day? When are you stressed? How stressed are you? Are you, you know, just having a really light dinner, and you're feeling like kind of anxious at night? Or you've got bright lights on? Just as for controlling your cortisol in the morning, you want to stack various things. Bright light exposure, caffeine, hydration, exercise, et cetera. In the evening, in order to get your cortisol levels right, in order to be able to fall and stay deeply asleep, you want to also stack these various things. No one's perfect about all of them. And if you can't control one of them, let's say you're under the bright lights at night because you're working late or you're at a concert, fine, that's life. You know, it's just kind of what a good life is. I don't think optimizing means not living or going to a concert, you know, this kind of thing, or being in a restaurant.

• 1:35:22Andrew D. Huberman?

  You need to live and enjoy your life, but maybe you do a few other things to be able to try and bring your cortisol levels down that evening. Things that are easily accessible and that are going to allow you to achieve what you want, which is to get a great night's sleep. Let's take a moment and talk about exercise late in the day. And when I say late in the day, I mean anytime after sundown, right? I think by now you already are realizing that the kind of ideal situation, regardless of whether or not you wake up later in the day, or you wake up at 5:00 a.m., or you're like Jaco, you wake up at 4:30 a.m. and you get into your exercise right away. The ideal situation for your cortisol rhythm would be to exercise early in the day. You know, I realize not everyone is an early riser, so when they hear that, they think, oh, I don't want to exercise early in the day, or I can't.

• 1:36:05Andrew D. Huberman?

  I'm not saying you necessarily have to exercise right as you wake up, but when you are thinking about your cortisol rhythm, the ideal pattern of exercising cortisol release would be where you exercise early in the day after sunlight exposure, under bright light exposure. We talked about all that before. But let's face it, some people can't exercise early in the day, and certainly not every day. We have schedules, we have constraints, and it's very important that we get our resistance training, and it's very important that we get our cardiovascular exercise on a regular basis. So if you're somebody who prefers to exercise at noon time, or 1:00 p.m., or 2:00 p.m., or 3:00 p.m., great. You already know, based on what we described about the endogenous pattern of cortisol release, that that's a time of day when it's really hard to trigger a positive feedback

• 1:36:50Andrew D. Huberman?

  loop on cortisol. So if you have a really grueling, hard, intense workout at 2:00 p.m., and before that, you drank an energy drink, or a big cup of coffee, or if you're me, some yerba mate plus a big cup of coffee, maybe an Alpha GPC every once in a while, I'll do that, and then- Hit the gym really hard in the early afternoon. You know, I prefer to do that in the morning. And I don't always take all those things before I work out. I only before resistance training do I drink caffeine usually. And only before really hard workouts do I do things besides drink caffeine. I'll do caffeine and Alpha GPC and, you know, in some cases, a lot of caffeine. But I get it, you know, some of you like to work out in the afternoon. And actually, if you look at the data on resistance training and athletic performance, the bulk of it points to the fact that

• 1:37:32Andrew D. Huberman?

  performance at those activities, strength, tends to be greater in the afternoon as opposed to the morning for most people. But the basic takeaway is train when you can. Train when it's available to you. But you don't want to spike your cortisol too late in the day so that it disrupts your sleep. So the good news is that if you train resistance training or cardiovascular exercise, doesn't matter, or a combination of the two, if that's what you're doing. If you end up doing that in the early afternoon or even as late as sundown, you're probably going to be okay. Your cortisol rhythm is still going to continue to drop. Your endogenous cortisol rhythm is going to continue to drop into the late evening and nighttime hours and you'll be allowed to sleep.

• 1:38:15Andrew D. Huberman?

  Yes, you will have to do certain things to ensure that happens. I would suggest eating some starchy carbohydrates, especially after a hard resistance training workout that comes later in the day. A hard, that is a moderate to high intensity exercise session has been shown to triple or quadruple your cortisol levels when it comes later in the day or in the evening. And remember, that's the time when you're basal, your endogenous cortisol levels are very, very low. So you get this big inflection in cortisol from the workout. So if you're going to work out much later in the day, like you're getting off work at 5:00 or 6:00 PM or 7:00 PM. I've had phases of my life when this was the case for me. And I still want to get my gym workout in and it's bright lights in the gym. I wasn't somebody who wore sunglasses in the gym. Sorry, back then we didn't have the wind down glasses. I wish I had had them. They would be great for a gym workout.

• 1:38:59Andrew D. Huberman?

  But I will caution you, those glasses do make it hard to see certain boundaries between objects. And you always want to prioritize safety over everything else. So if you're in a gym, bright lights, working out at 5:00 or 6:00 PM, you do your hard workout, when you walk out of there, your cortisol levels are ratcheted way up. This is just the reality and there are good data on this. Now, that's not necessarily a problem, but your goal is to fall asleep that night. So it would be very wise to certainly get some quality protein, but also some starchy carbohydrate, probably some fruit or something else to really get your glycogen stores replenished again. But you're also going to want to do some long exhale breathing. Maybe just take two or three minutes and do some long exhale breathing after your workout

• 1:39:42Andrew D. Huberman?

  in your car before you drive home or when you get home. You want to take a hot shower. Great if you can sit in a sauna, then take a warm shower, kind of a neutral shower, not a cold shower that's going to like blast your, your stress levels up. You know, take a nice mellow shower. You just want to do some things to bring your cortisol levels down, increase the levels of that parasympathetic autonomic activity. Long exhale breathing, starchy carbohydrates, dim the lights, hot showers, great sauna if you have access to it. Take everything down a notch and then certainly, certainly don't stimulate your nervous system with bright light of any kind, right? Red light, dim light, wind down glasses, all that's going to help you, but don't get on your phone or computer right before getting into bed because you've already spiked your

• 1:40:25Andrew D. Huberman?

  cortisol from that workout and your basal cortisol levels are low. And so it's a perfect time to send yourself into later hours of the night when your cortisol is way too high. And the big problem there is not only will it disrupt your nighttime sleep, but it also disrupts your next morning cortisol levels. I'm going to remind you how that happens in a moment, but before we do that, I'm going to remind you of this really terrific study that we discussed at the beginning of this episode was, I'll repeat the title again, 24 hour pattern of the episodic secretion of cortisol in normal subjects. And remember, there's this phase one, they've referred to it as a six hour period of minimal secretory activity. That means extremely low levels of cortisol being released that spans from four hours

• 1:41:10Andrew D. Huberman?

  before and two hours after lights out. Four hours before and two hours after going to sleep.

• 1:41:18Andrew D. Huberman?

  That's when you want your cortisol lowest. So if you're working out in the late evening and closer to sleep, you're going to need to do a number of things to really try and offset any increases in cortisol. It's so critical that you get this phase one correct. And the reason is if your cortisol is spiked, then even if you do a bunch of things to be able to fall asleep, you're going to blunt your next morning cortisol and you know why that would be the case. Think about it.

• 1:41:46Andrew D. Huberman?

  The whole rhythm in cortisol is generated by this negative feedback loop. Where cortisol levels get too high, your hypothalamus suppresses the creation of more cortisol. So if at night, when your cortisol is supposed to be especially low, you spike your cortisol and it stays up too long, you don't do things to bring it down after a workout, or you drank too much caffeine before that workout, and then you really are up late and the whole thing starts to span into the hours that you really should be sleeping, what's gonna happen? What's gonna happen is the next morning, your cortisol levels are going to be suppressed because your hypothalamus is seeing levels of cortisol that are far too high, much higher than normal. And so the next morning, you're gonna feel sluggish. You're gonna have a hard time waking up. You're gonna have a really hard time focusing.

• 1:42:30Andrew D. Huberman?

  You're gonna feel like you're in a fog. And most people deal with this by what? By drinking more caffeine, which on its own is not a terribly bad thing, right? It's going to prolong the release of cortisol, but it's not going to spike the increase in cortisol. So if you screw up and you train too late, and you drank caffeine before, and you don't have the opportunity to dim the lights, you're not doing your long exhale breathing, and you have this, you know, you basically are eating into the hours that you should be sleeping, or you spike your cortisol some other way, you get into an argument before sleep, or you're up late because you're dealing with some stress. Guess what? The next morning, especially if you've had a shortened night of sleep, especially if you had stress the night before of any kind, you want to take an extra effort to spike your cortisol levels.

• 1:43:14Andrew D. Huberman?

  You're going to need to try and boost your cortisol levels even higher through bright light, hydration, maybe not exercising again if you already trained the night before, maybe cold shower. You're really going to want to do all the things you can to try and spike your cortisol so that at least the next day and the next night, your cortisol levels are back on track. So many people get this wrong. And for years, I got this wrong. I would occasionally work out in the morning, then I'd work out in the evening. And then I noticed that my schedule just was getting tougher and tougher to adhere to because some mornings I was dragging, other mornings I was feeling great because I got to bed early the night before. The whole thing was kind of a mess. If I had only understood that if I were to have some stress the night before going to sleep, anytime in that first secretory phase, as it's referred to,

• 1:43:57Andrew D. Huberman?

  the four hours before and the two hours after sleep, any stress that eats into that period. Whether it's exercise caused or psychologically caused, excuse me, whatever, needed to be offset by spiking my morning cortisol more using the various tools that I've described. So you now understand the global rhythm in cortisol, higher in the morning and you want to amplify that. Lower in the afternoon and evening, dropping in the early afternoon, later afternoon and evening. And then ideally staying low at nighttime. So that they can come back up again in the morning. So if you're exercising late in the day, that's when you can do it, that's when you like to do it. Great, but do things to bring your cortisol levels back down. Okay, let's talk about compounds, AKA supplements that one can take to reduce their cortisol.

• 1:44:42Andrew D. Huberman?

  Since your goal is to reduce your cortisol in the evening and at night. There are many supplements that have been purported to reduce cortisol. These include things like ashwagandha, apigenin, which we'll discuss, things like phosphatidylserine, even rhodiola. There are a long list of things that have been purported to reduce cortisol. However, there's a short list of things that have been shown to do that relatively potently and to act pretty quickly and that are generally available out there. The most commonly discussed one in the context of reducing cortisol is ashwagandha. Now, if you look at the literature on ashwagandha, you will see that indeed it can be effective in reducing cortisol levels. By anywhere from about 11% to 29%. And there may be studies that fall outside those margins.

• 1:45:26Andrew D. Huberman?

  But if you look at the best studies, that's really what it points to. Now, here's a key thing. You already know that you want your cortisol levels relatively high to high early in the morning. And through the mid morning and dropping into the early afternoon. And you want them low in the late afternoon and at night. So if you're going to experiment with ashwagandha as a means to reduce your cortisol levels. And you're going to take ashwagandha at the dosages that significantly decrease cortisol levels, which would be dosages somewhere between 300mg and it's been explored all the way up to 900mg. But typically, I would recommend if you're going to explore ashwagandha, that you would explore lower dosages. Somewhere in the neighborhood of 300mg at least to start, right? You always want to look for the minimal effective dose.

• 1:46:09Andrew D. Huberman?

  That you restrict your intake of ashwagandha to the late afternoon. And evening and nighttime hours to keep your cortisol levels low. And that you avoid taking dosages of ashwagandha. Certainly as high as 300 milligrams anytime early in the day. In fact, if you're going to take ashwagandha and it is contained in various compound blends like AG1 and other things, but at very low levels, low milligram count. That's going to be fine early in the day, anything less than say 50 or 100 milligrams early in the day. Not going to have a significant impact on cortisol. But taken later in the day in order to reduce your levels of cortisol, 300 milligrams, 600 milligrams. That really should just be restricted to later in the day for obvious reasons, or at least they should be obvious to you now.

• 1:46:52Andrew D. Huberman?

  So, as I mentioned, there are data pointing to the fact that ashwagandha can reduce cortisol levels. By a significant degree, you still need to do, and ideally you are already doing all the various things to reduce your cortisol levels before you even take ashwagandha or experiment with it. I always recommend that you do the behavioral things first. And then decide whether or not you need supplementation in order to further increase in effect like lowering cortisol in the evening and at night. So dimming the lights, not drinking too much caffeine. If you're exercising, bring your levels of autonomic arousal down. All the things I just talked about a moment ago. You have to be doing those things. It's not going to be sufficient to just take 300 to 600 milligrams of ashwagandha and keep your cortisol levels low. If you're blasting your eyes with bright light, you're under a lot of stress at night.

• 1:47:38Andrew D. Huberman?

  But because it can produce a significant reduction in cortisol, it can augment your overall program for trying to keep cortisol low in the evening and at night. The other compound that some of you might be interested in for reducing cortisol levels, again in the evening and at night, is apigenin. Apigenin is found in chamomile tea. Chamomile tea is long known to be a, you know, sort of relaxing agent, but apigenin comes from chamomile. You can take apigenin as a concentrated capsule, right? I do that. It's actually in the sleep stack that I've taken for years and that I've, I don't recommend in the sense that everyone has to take it. But I've talked about apigenin before in the context of the so-called Huberman Lab Sleep Stack, which is a stack of apigenin, magnesium, three and eight.

• 1:48:23Andrew D. Huberman?

  Which by the way is interchangeable with bisglycinate for sleep, but 3-ane is going to be better for a variety of reasons. So apigenin, magnesium, 3-ane and theanine is the so-called Huberman Lab Sleep Stack that has worked exceptionally well for me. I've taken it for many years. Apigenin, because it works on both the GABA pathway and some chloride channel pathways, has been shown to decrease cortisol. Now, it's not as big an effect on reducing cortisol as is ashwagandha at dosages of 300 milligrams or more, but I take 50 milligrams of apigenin in capsule form every night before I go to sleep. I've been doing that for well over eight years now, and will continue to because I find it's very helpful for my sleep. And here's a great opportunity for me to also say that

• 1:49:06Andrew D. Huberman?

  there's evidence that Mag 3-ane can indirectly activate pathways that might further help suppress cortisol. So it makes sense why the Sleep Stack would include apigenin, why apigenin can be useful for sleep because of reducing cortisol. Again, the four hours before sleep and the two hours after sleep are this key time for keeping cortisol low. The logic I'm using is that apigenin is useful for enough things related to sleep and reducing cortisol that it makes sense to keep in my evening routine. I do take ashwagandha at a dosage of 300 milligrams. I take it, of course, in the evening and at night. If you're going to do anything to reduce your cortisol in the evening and at night, the best timing for that is going to be sometime after dinner, right? I'm not going to say it's always 30

• 1:49:49Andrew D. Huberman?

  minutes before sleep or 60 minutes before sleep. I tend to take apigenin and magnesium 3-ane about 30 to 60 minutes before I want to fall asleep. But the ashwagandha can come pretty much at any time in the evening with dinner or after dinner, frankly. Its effects are known to last many hours, and that's the time when you want your cortisol lowest. I want to reiterate supplementation should never be the first line of attack when you're trying to adjust some biological mechanism or some health metric. I mean, there are cases where people need prescription medication for that. I do think when it comes to supplementation, that you not only get the best effects, but you understand whether something's working for you at a given dosage, if it's worth your money and time, et cetera, only once

• 1:50:32Andrew D. Huberman?

  you're doing all the behavioral things right. I can't emphasize this enough. Unless you're getting your behavioral steps correct, supplementation just doesn't make a whole lot of sense. That said, Rational supplementation with things like ashwagandha and apigenin, maybe magnesium 3-ate as well. They make sense from a mechanistic level. There are decent enough studies in humans to support their use for reducing cortisol. And if you're somebody who's really trying to optimize your cortisol patterns across the 24-hour cycle, I do think they can be a useful tool, which is why I take them. Okay, let's talk about burnout. A lot of people will say, "I'm burnt out. I'm just like exhausted." Or, "I'm wired and tired," which is frankly the worst kind of burnout, because it's the

• 1:51:14Andrew D. Huberman?

  kind of thing where you're like still going, but you're exhausted. Burnout is a real thing. Okay, burnout reflects a number of different processes in the brain and body, but the one thing it doesn't reflect is that your adrenals are gone, or that they can't secrete adrenaline, or that they can't secrete cortisol. Yes, there are certain medical conditions like Cushing's or Addison's. Cushing's is hyper-elevated cortisol. Addison's is basically adrenal insufficiency. Okay, it's an autoimmune condition where your adrenals literally can't release cortisol and adrenaline. But, most people out there who are feeling burnt out are not dealing with Addison's. Okay? Most people out there who are feeling burnt out are not dealing with Cushing's. If you think you're dealing with Cushing's, if you're dealing with like really rounded

• 1:51:58Andrew D. Huberman?

  face, accumulation of body fat around your midsection, you're feeling super stressed in the morning and other times of day, and you really feel like you're suffering from what might be hyper-elevated cortisol levels, please see a doctor, ideally an endocrinologist, there are great treatments for this that involve suppressing cortisol using medication at certain times of day. There's a test called the dexamethasone suppression test, where you take a drug that mimics cortisol late at night, you see if it suppresses your cortisol the next morning. There are all sorts of things that you can do to assess whether or not you actually have Cushing's, or you actually have Addison's. And those need to be dealt with, with a medical doctor. However, most people out there who are struggling with burnout do not suffer from either of those conditions. So. Does that mean burnout isn't real? Or that we can't deal with it?

• 1:52:42Andrew D. Huberman?

  No, burnout is very real. However, most people don't understand burnout, or they try and go about treating burnout in exactly the wrong way. And here's the reason for that. There are really two patterns of burnout, and this has been explored in the literature through the lens of trying to understand when cortisol is elevated and when it's lower across the 24-hour cycle, and people that are saying, "I'm burnt out. I'm wired and tired. I'm suffering from brain fog. I'm getting sick all the time. I'm just exhausted." Or, "I just, I feel like I'm, just can't keep up with life." Now, there can be a lot of reasons for those statements, psychological and otherwise. It's never just physical or just psychological. Of course, the two things intersect. But here's the good news. Those two forms of burnout, you can figure out which one you have.

• 1:53:26Andrew D. Huberman?

  And those two forms of burnout each have different approaches that they require in order to fix them. So, let's talk about the first pattern of burnout, which is when people are waking up feeling super stressed. They're waking up with anxiety, ideally after some sleep, but maybe it's after just, you know, three, four hours of sleep. Like, they can't fall back asleep, and they're feeling just completely activated first thing in the morning, maybe far too early in the morning. And then maybe they maintain that level of stress and activation into the early afternoon. Maybe they don't, but more typically, they crash in the afternoon. They're just feeling exhausted by the afternoon, and they're just staring at the computer screen or just feeling like they're in a fog, they're forgetting things. That's one very typical pattern of burnout. The other pattern of burnout

• 1:54:10Andrew D. Huberman?

  is when people are feeling like they're waking up and they're just really sluggish. They don't have energy. They've got brain fog. They're drinking caffeine. They're hydrating. They're trying to do all the things, and they're just like, they don't even have the energy to do them. And they just can't get into gear. They have no get up and go. But then, when evening rolls around, they can't slow down. They can't calm their mind. They can't fall asleep. They're tired, but they're wired. Okay. As you can see, those are two very distinct patterns of stress, of burnout. And as you can imagine, they require perhaps the same steps or different steps, but certainly at different times in order to resolve that burnout, in order to fix it. You now know what those steps are.

• 1:54:55Andrew D. Huberman?

  But first you have to ask yourself, if you're burnt out, which pattern are you suffering from? Now, I know a number of you are gonna shout out, I'm suffering from both of them. I'm like exhausted all day and morning. Okay. We could easily create a third category of burnout whereby you're just exhausted all the time, morning, day and night. But if you're really exhausted at night, why aren't you falling asleep? Probably because your mind is racing and you're too stressed. You're falling asleep and then you're waking up after a couple of hours. So you'd fit probably more into the second pattern of burnout, late phase burnout, as opposed to early phase burnout. So just to get clear on our terms, the first pattern of burnout is super stressed in the morning, exhausted in the afternoon, evening and at night.

• 1:55:38Andrew D. Huberman?

  Second pattern of burnout, stressed at night, exhausted in the morning. You are now armed with the various tools to be able to correct either pattern of burnout. If you're waking up with a ton of stress, maybe even a few hours before you should be waking up or want to wake up in order to get your full complement of sleep, you need to do something to try and bring down or to reduce the angle on that rising cortisol first thing in the morning. Because almost certainly, your cortisol is just rising too fast. Remember, your cortisol is supposed to start rising a couple of hours before you wake up. It's not supposed to be what we call a square wave function, like go from flat to vertical. Okay? Here's what you should do.

• 1:56:23Andrew D. Huberman?

  If you're waking up with a ton of stress, you're not sleeping enough, I highly recommend that you use a practice I've talked about before in this podcast, which is non-sleep deep rest, AKA yoga nidra. Some people call it yoga nidra. I call it non-sleep deep rest. There are some differences between the two. Not trying to take anything away from the practice of yoga nidra. But basically, non-sleep deep rest, AKA yoga nidra, involves doing some long exhale breathing for reasons that you now know slows your heart rate down. It involves deliberately relaxing your body.

• 1:56:54Andrew D. Huberman?

  It also involves you learning how to deliberately engage your parasympathetic nervous system. Now, some people will do NSDR or yoga nidra first thing in the morning when they wake up to avoid too much stress, and they'll fall back asleep. NSDR, non-sleep deep rest. The idea with yoga nidra and NSDR is that you don't fall back asleep, that you stay awake, but you completely and progressively increase your relaxation in your body. However, if you fall back asleep, great, just make sure you set an alarm if you're going to do NSDR or yoga nidra first thing in the morning, so that you don't oversleep and, you know, miss a work appointment or something like that. But there are great data now showing that NSDR and yoga nidra, done regularly for durations of anywhere from 10 minutes, actually, the study I'm going to be referring to in a moment

• 1:57:38Andrew D. Huberman?

  actually used 11 minutes. Okay, so anywhere from 11 minutes to 30 minutes can significantly reduce cortisol levels. So this is good, right? Even though we've been talking this whole episode about you want your cortisol high in the morning, we're referring to a pattern of burnout where your cortisol is rising too fast in the morning. Doing NSDR can help adjust that slope so that it's not so steep. In fact, if you're somebody who wakes up and feels anxiety right away, even if you don't think you have this pattern of burnout, I highly recommend doing a 10-minute, or even a 20-minute or 30-minute NSDR. It's available at completely zero cost. You don't have to sign up for anything. I'll provide links to this in the show note captions. There are several, some read by me. These are in pure audio form or combined audio/video form.

• 1:58:21Andrew D. Huberman?

  You don't need to watch them, but we have them on YouTube, we have them on Spotify, we have them in Apple format, we have them in a bunch of different formats. And I also provide links to some of the ones that are read by other people whose NSDRs are very effective and that I personally use, such as Kelly Boyes and others, who have recorded NSDRs of different durations. It's an extremely powerful tool for reducing your cortisol levels. But in addition to that, it's a very powerful tool for you to be able to self-direct your own Activation of that parasympathetic nervous system to self-direct your own relaxation at a time when your system is by default driving you in the exact opposite direction. So if you're somebody suffering from this first type of burnout, I highly recommend you start implementing an NSDR practice, especially if you wake up in the middle of

• 1:59:05Andrew D. Huberman?

  the night, you wake up really early in the morning, and you can't just naturally fall back asleep. Okay, so ideally, you're doing NSDR right as you wake up in the morning. Ideally, you do it for 30 minutes, but most people probably won't have the time for that. So maybe you do 20, maybe you do 10. Again, we have zero-cost scripts for all of those, 10, 20, and 30 minute long. You wake up. The first thing you should do is hydrate. Well, use the restroom if you need to, then hydrate. You might say, wait, hydration is going to raise my cortisol more. Trust me, hydrate. Also, get bright light in your eyes. This is going to help adjust the timing of your maximal cortisol peak. In circadian nerd speak, it's called the acrophase. Believe it or not, they call the peak of your cortisol peak on the 24-hour cycle, the acrophase. They needed to give it a name.

• 1:59:50Andrew D. Huberman?

  So your acrophase is going to be timed correctly to when you're waking up, not before waking up. Okay, so we're doing one thing, NSDR, yoga nidra, to try and keep your brain and body in a more sleep-like state, and now we're going to do another thing right after you wake up to try and make the peak in your cortisol, your acrophase, after that. Okay, so we're trying to shift that peak out a little bit by hydrating and by getting bright light in your eyes, ideally from sunlight, if not sunlight, 10,000 lux artificial light, as we discussed earlier. Here's the thing that you don't want to do. You don't want to ingest caffeine right away. If you recall, the reason for suggesting that some people push their caffeine intake out 60 to 90 minutes after waking is because caffeine will extend the duration over which

• 2:00:35Andrew D. Huberman?

  cortisol is available. And if you drink caffeine first thing in the morning, yes, that will happen, but the drop in cortisol that occurs late morning and early afternoon is going to be very, very sharp, and you want to make that a little bit flatter. Now, a little bit later, we're going to talk about how a flattening of the cortisol curve is a bad thing, but here, we're just trying to make it a little bit flatter by shifting your caffeine intake out a little bit. Not only will this help you get through the afternoon with more energy, and by the way, ingesting it 60 to 90 minutes later than you normally would after waking is not going to disrupt your sleep at night. But it's going to make sure that you have enough energy to get through the afternoon. And it's also going to make sure that that morning cortisol peak isn't too high and too long, too early.

• 2:01:20Andrew D. Huberman?

  Okay, so we're just trying to shift that peak out a little bit. And then we're trying to make that drop in cortisol a little bit longer. This might seem like subtle details, but these subtle adjustments in these behaviors can have a significant impact on how much energy you feel and how distributed that energy is across the day in ways that are going to benefit you. Okay, so now let's talk about the second pattern of burnout. The second pattern of burnout is the one where people are waking up tired, they're dragging through the morning despite presumably drinking a lot of caffeine, they can't get into gear, they have brain fog in the afternoon, or maybe they really start to feel like they're awake at 2 o'clock in the afternoon, and they have trouble falling asleep at night, often from stress and exhaustion. So it's not like they're hyper-functional at night, getting a ton done.

• 2:02:04Andrew D. Huberman?

  That would be, I should mention, the kind of night owl pattern. I don't want to be disparaging of or discourage night owls. If you're naturally a night owl, and that works for you, it works with your work, it works with your schooling, works with your relationships, great. Okay, I'm not a night owl, but some percentage of people are night owls. There's a chronotype, a genetic wiring that makes certain people night owls. But real classic night owls, when they follow a night owl schedule, their cortisol rhythm is exactly the same as everyone else's, it's just shifted a few hours later. Okay, so it's not like the contour of their cortisol rhythm looks any different, it's just shifted later. And night owls typically, if their life allows for it, like being night owls. With type 2 burnout, I'm not talking about that. I'm talking about people that at one point in their life felt pretty good waking up at, you know, between 6 and 8 a.m. in the morning, which is when most people wake up

• 2:02:49Andrew D. Huberman?

  in the morning. I'm talking about people who would like to go to sleep by 10 or 11 p.m., but they're not able to do that. I'm talking about people here, again, that have trouble getting into gear early in the day, and then come nighttime, their levels of energy and certain mental ruminations and, you know, just their stress levels are just really high, even if they're exhausted. If this is you, you really need to start thinking about the six hours before you would like to fall asleep and the two hours afterwards. How do you do that? Well, I already talked about all the things you should avoid doing in the evening, avoiding bright light, et cetera. By the way, if you are in the long days of summer and spring and the sun is going down at, you know, 7:30 or 8:30, that's fine.

• 2:03:34Andrew D. Huberman?

  In fact, we now know that if you view sunlight late in the day, provided the sun is out, which is the only way you can view sunlight, as far as I know. Viewing that sunlight will actually adjust the sensitivity of your retina a little bit, such that bright light from artificial sources won't have quite as much of a detrimental effect at suppressing melatonin at night when you're indoors under artificial lights. You still want to dim them late at night, but by all means, if there's a beautiful sunset out, take a sunset walk, walk in the direction of the sun, look at the sunlight, blink as needed to protect your eyes, but see those beautiful sunsets. You'll notice that throughout today's episode, I've not focused on specific clock times. I've given ranges. Most people wake up here, most people go to sleep here. I've given ranges because, of course, day length changes across the year, especially if you're living closer to the poles.

• 2:04:19Andrew D. Huberman?

  So if you're somebody who's suffering from type 2 burnout and it's 7:30 at night and the sun's still out, by all means, go for a nice relaxing walk. That's going to be part of your regimen for bringing down your levels of autonomic activation, for reducing your cortisol. By all means, also avoid caffeine. By all means, also avoid stress. And when you get indoors, by all means, do everything you can to dim the lights, to bring your levels of stress down. Take five minutes. I know it sounds like a lot, but just five minutes and do a physiological sigh of the sort that I described before, double inhale, long exhale, and just repeat that for about three to five minutes. I ran a clinical trial with my colleague David Spiegel at Stanford a few years ago where we had people do that.

• 2:05:01Andrew D. Huberman?

  And what we found is it not only calms them in those five minutes, not only reduces heart rate, increases heart rate variability, which is a signature, by the way, of self calming.

• 2:05:12Andrew D. Huberman?

  It also improves sleep, it improves mood at times outside of that five minutes. It's a very powerful tool. And again, five minutes is barely anything. But if you take that time, you're going to benefit from that certainly in the time that you're doing it and in the hours after with the ease of being able to fall asleep, but also the next day. So much of recovering from burnout, especially type 2 burnout, is about getting your nighttime cortisol low so that your morning cortisol levels can be elevated again and that you can have that energy in the morning, which then sets in motion the proper overall cortisol rhythm. If you're starting to sense a repeating theme, indeed, it's because your cortisol rhythm is repeating. And you've got that peak that ideally comes in the morning.

• 2:05:54Andrew D. Huberman?

  And then you have that trough, what in nerd speak we call the nadir, right? Peak is the acrophase. Scientists are, I don't know, I don't know if they're just making up names for fun or they just, they need this. Peak and acrophase are the same thing, nadir or trough in cortisol is coming late at night and as you fall asleep and into the early hours of sleep. Having that pattern and having those peaks and the trough aligned to the right time of your schedule for you, for what you need to do in life, for your kids, for your job, for school, for athletics, et cetera, is so critical and it's absolutely under your control. And I see so many areas of health and wellness, so many areas where people are trying to troubleshoot illness, like they're getting sick all the time, or they're dealing with

• 2:06:36Andrew D. Huberman?

  an autoimmune issue, or they're dealing with metabolic issues and things of that sort. And so many times, it seems that what's happened is this cortisol curve has just shifted too late, or it's being spiked in the afternoon, or it's being spiked at night. And yes, we could talk about all the reasons why with modern electronics and technology, you know, we're biasing ourselves towards these, these patterns of late shifted cortisol and disrupted cortisol rhythms. But look, technology is not going anywhere. What is here to stay is your ability to engage with those technologies and to do the proper things like exercise and eating, et cetera, and self calming at the appropriate times of your schedule so that you can get your cortisol rhythms back in check. And I promise you, if you do that, you're going to see an outsized positive effect

• 2:07:21Andrew D. Huberman?

  on everything, mood, focus, alertness, sleep, which then of course feeds back on elevated mood, focus, alertness and sleep. The early part of your day, the middle of your day, and the end of your day and night are linked. What are they linked by? Your cortisol rhythms. How do you control those cortisol rhythms? By grabbing a hold of the time of day in which they're most challenging. And starting to do as many things as you possibly can to bring your cortisol up, if that's what's needed early in the day, or down, which is what's needed late in the day. Wherever your main pain point is along the 24-hour day and night, that's where you should focus your efforts first. And from there, you can start making adjustments in the other protocols in order to get things exactly right for you.

• 2:08:03Andrew D. Huberman?

  It's possible, but start where you're experiencing the most pain first. In fact, so much of what we see out there in the discussions around health and challenges with health, whether or not it's chronic stress, or whether or not it's challenges as we age in getting great sleep and having energy. If you look at the literature, it almost always comes back to cortisol. Maybe not as the only problem, but as a key role in those problems and a key path to fix them. In fact, there's a beautiful paper that compared male and female differences in cortisol secretion patterns. And they look pretty much similar up until about age 40. Actually, what you find is that women have slightly lower basal levels of cortisol, if you look at any one time point along the 24-hour rhythm, up until about age 40.

• 2:08:46Andrew D. Huberman?

  Then what happens is, as men and women get older, from about 40 out to 70, they look across a pretty broad range of ages. What you find is that the morning peak in cortisol tends to come down a little bit. In fact, the acrophase, that peak, tends to be a bit more rounded as opposed to peaked, which means that the drop in cortisol in the early afternoon and evening is actually more gradual. It's flattening. And a flattening of the cortisol curve has been shown in other studies to actually predict lower lifespan, certainly in response to health challenges like cancer. And here's the good news. Practices which adjust stress down in the afternoon in those people combating cancer actually predicted survivability. In other words, the bigger the peak, the more rapid the decline in cortisol into the afternoon,

• 2:09:29Andrew D. Huberman?

  and the lower it stayed at night, the longer people lived, and the more successful people were in overcoming diseases such as cancer. Now, I'm not saying that's the only thing that allowed them to do that, but it makes perfect sense based on everything we know about the interactions between cortisol and the immune system, between stress and survivability, between longevity, and between the production of all sorts of things that relate to glucose metabolism, dopamine, et cetera, and so on. Another interesting point is that as women transition from perimenopause to menopause, so of course, this is correlated with aging, but the exact age that it occurs differs between women. But it's roughly between the ages. Of late 30s to early 50s, depending on the person. There's also a characteristic flattening out of the cortisol rhythm into the afternoon.

• 2:10:13Andrew D. Huberman?

  That's the way it's described in the literature across all these different situations. Menopause, aging, when people are combating a chronic illness and so forth, is this flattening of the afternoon cortisol curve. What this speaks to, again, is the critical importance of high morning cortisol. You want to emphasize that. Yes, you want to get enough sleep, but you want high morning cortisol. You want to get out and into your day. If that day for you starts at 4:00 AM, okay. If it starts at 5:00, 6:00, 7:00, 8:00 AM, okay. We're not talking about the exact time you wake up, but you want to get enough sleep prior to that. For most people, it's going to be six to eight hours. There are you rare ones out there that can get by on four to five hours, but the data really points to the fact that most people should get six to eight hours, maybe nine, or maybe more if you're a kid and you're developing

• 2:10:58Andrew D. Huberman?

  or you're combating, you know, an illness or something. But six to eight hours, when you wake up, spike that cortisol using the tools we described. Then make sure that cortisol doesn't come down far too fast, right? You don't want a vertical drop in it. This isn't like a roller coaster at one of these theme parks. It's like basically a vertical drop. You want a relatively steep drop and you want that cortisol coming down, down, down, down, down, into the afternoon, such that by late afternoon and evening, it's down. And then you want to keep it down. You want to do things to stay calm. It doesn't mean that you can't go out and have a good time. It doesn't mean that you can't have a dinner party and engage in that. You can do those things, but those aren't stressful things. Keep your stress levels down, keep your cortisol levels down, certainly as you transition into sleep.

• 2:11:42Andrew D. Huberman?

  If you can master this pattern for just three to four days, you're going to notice a significant improvement in your overall well-being. Every metric of well-being, energy, focus, et cetera, sleep quality, and on and on. And in fact, we didn't go into it today, but there is a vast literature that shows that if you get your cortisol rhythm right, it improves your cognition. There's also a vast literature showing that if your cortisol is disrupted in a way that your cortisol is too high in the afternoon, your cognition suffers. There's actually a known reason for this. I can't help but sneak this in, which is that your hippocampus, this brain area that's involved in learning and memory, is chock a block full of cortisol receptors. And what happens is if your cortisol is elevated at the wrong times for too long,

• 2:12:28Andrew D. Huberman?

  You actually get degeneration of these neurons in the hippocampus. It's a bad situation for two reasons. One, cognition and memory suffer. The other reason is that the hippocampus itself is involved in contextual control over the cortisol cycle, meaning the hippocampus is vital for you to be able to interpret when something is merely arousing, exciting versus stressful. And so as that structure degenerates, you can't remember as many things, which itself is stressful, but also your ability to regulate stress is reduced. There are literally hundreds of studies on this from animals and in humans. So getting your cortisol rhythm correct and controlling it is going to serve you immensely well. Having the cortisol pattern of high in the morning, low in the afternoon and at night

• 2:13:13Andrew D. Huberman?

  is the cortisol pattern you want, which means that everything that we've talked about today in terms of protocols, whether or not they are behavioral, involving exercise, whether or not they're involving nutrition, whether or not they're involving supplementation. Although I should say for supplementation, I recommend that kids not use supplements to control cortisol. I should say if you're 18 or younger, you should be really cautious about using supplements of any kind. There are a few like creatine, which may be okay, or some whey protein. If your parents decide it's okay, talk to your parents, kids. But certainly if you're 18 or older, all the things that we've talked about today are applicable for getting your cortisol rhythm right. Thank you for joining for today's discussion about cortisol, how to regulate it for sake of overcoming burnout and just generally for improving your health and navigating life more effectively by controlling your cortisol rhythms.

• 2:13:58Andrew D. Huberman?

  If you're learning from and or enjoying this podcast, please subscribe to our YouTube channel. That's a terrific zero cost way to support us. In addition, please follow the podcast by clicking the follow button on both Spotify and Apple and on both Spotify and Apple, you can leave us up to a five star review and you can now leave us comments at both Spotify and Apple. Please also check out the sponsors mentioned at the beginning and throughout today's episode. That's the best way to support this podcast. If you have questions for me or comments about the podcasts or guests or topics that you'd like me to consider for the Huberman Lab podcast, please put those in the comments section on YouTube. I do read all the comments. For those of you that haven't heard, I have a new book coming out. It's my very first book. It's entitled Protocols, An Operating Manual For The Human Body. This is a book that I've been working on for more than five years and that's based

• 2:14:43Andrew D. Huberman?

  on more than 30 years of research and experience and it covers protocols for everything from sleep. To exercise, to stress control, protocols related to focus and motivation. And of course, I provide the scientific substantiation for the protocols that are included. The book is now available by pre-sale at protocolsbook.com. There you can find links to various vendors. You can pick the one that you like best. Again, the book is called Protocols: An Operating Manual for the Human Body. And if you're not already following me on social media, I am Huberman Lab on all social media platforms. So that's Instagram, X, Threads, Facebook, and LinkedIn. And on all those platforms, I discuss science and science-related tools, some of which

• 2:15:25Andrew D. Huberman?

  overlaps with the content of the Huberman Lab podcast, but much of which is distinct from the information on the Huberman Lab podcast. Again, it's Huberman Lab on all social media platforms. And if you haven't already subscribed to our Neural Network newsletter, the Neural Network newsletter is a zero-cost monthly newsletter that includes podcast summaries, as well as what we call protocols, in the form of one- to three-page PDFs that cover everything from how to optimize your sleep, how to optimize dopamine, deliberate cold exposure. We have a foundational fitness protocol that covers cardiovascular training and resistance training. All of that is available completely zero cost. You simply go to hubermanlab.com, go to the menu tab in the top right corner, scroll down to newsletter, and enter your email. And I should emphasize that we do not share your email with anybody.

• 2:16:08Andrew D. Huberman?

  Thank you once again for joining me for today's discussion, all about cortisol. And last, but certainly not least, thank you for your interest in science.

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