Your Skin’s Worst Enemy Isn't the Sun - It's Your Metabolism!

Healthy skin isn't built in your bathroom—it’s built inside your body. While most people focus on creams, collagen powders, and cosmetic treatments, the biggest drivers of wrinkles, sagging, and loss of elasticity are happening at the cellular level. In today's episode, I discuss: Why blood sugar may be aging your skin faster than the sun and the hidden process that damages collagen from the inside out The surprising connection between muscle, metabolism, and firmer, healthier-looking skin (especially after weight loss) How your body's natural cellular repair system helps slow the aging process and the habits that activate it The biggest everyday factors accelerating skin aging, and the science-backed strategies that help protect your skin for years to come Healthy skin isn't something you can simply apply—it's something your body creates. By improving your metabolic health, protecting collagen, building muscle, reducing inflammation, and supporting your cells, you can help your skin stay stronger, healthier, and more resilient from the inside out. Resources Mentioned: Environmental Working Group (EWG): https://www.ewg.org/areas-focus/personal-care-products Track your health with Function Health: https://functionhealth.com/mark (Use code MARK2026 for $50 off your membership.) Have a question you’d love answered on Office Hours? Submit it here (0:00) Understanding Skin Aging and Its Causes (1:24) Sponsor: Function Health (2:04) Chronic Inflammation, Blood Sugar, and Glycation in Skin Aging (6:01) Autophagy and Lifestyle Habits for Skin Health (9:31) The Role of Muscle and Managing Loose Skin (12:11) Sun Exposure, Protection, and Skin Aging (14:35) Rapid Fire: Common Skin Health Questions

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

• 0:00Dr. Mark Hyman?

  Can you naturally slow your skin aging and reduce skin sagging by improving your metabolic health? Well, the best anti-aging treatment for your skin isn't sitting on your bathroom counter. It's happening inside your cells. Most people think younger looking skin comes from finding the perfect moisturizer, the best collagen powder, or the newest anti-aging treatment. Those things can certainly help, but they don't address the biology that's actually driving your skin aging. And here's the truth. Your skin doesn't age from the outside in. It ages from the inside out. Every wrinkle, every loss of elasticity, every bit of sagging reflects changes happening deep inside your cells long before you ever notice them in the mirror. Today, I'm going to show you five biggest things that accelerate skin aging and more

• 0:44Dr. Mark Hyman?

  importantly, what you can actually do about them. We're going to talk about why some people develop loose skin after losing weight, my blood sugar, maybe aging your skin faster than the sun. What's one of your body's most powerful cellular repair system and what it has to do with healthy aging? And we're talking about the simple daily habits that help your skin stay stronger, healthier, and more resilient over time. Because healthy skin isn't something you apply. It's something your body builds, one healthy cell at a time. Here's the first thing most people don't realize. Your skin age isn't just reflecting your age. It's reflecting your health because your skin is much more than a surface. It's your body's largest organ and like every other organ, this health depends on the health

• 1:25Dr. Mark Hyman?

  of your cells, which means if you want a healthier looking skin, you have to start by building a healthier body. This episode was brought to you by Function. Get access to over 160 lab tests annually at functionhealth.com/mark. Most people don't think of skin as an organ, but it is. In fact, it's your body's largest organ. Its job simply isn't to make you look younger. It's protecting you every second of every day. It regulates temperature, supports immunity, keeps bacteria out, produces vitamin D, and it's constantly repairing itself, which means the health of your cells are the health of your skin becomes. And that brings us to the first thing that ages your skin. Chronic inflammation. Inflammation's wonderful when it's short-lived. It's how your body heals. If you cut your finger, inflammation helps stop the bleeding.

• 2:09Dr. Mark Hyman?

  It fights infection, helps rebuild the healthy tissue. If you lift weights, a small amount of inflammation signals your muscles to repair and become stronger. That's exactly what it's supposed to do. The problem isn't inflammation. The problem is when your body never gets the message to turn it off. And that's what we call chronic low-grade inflammation. Now, unlike other inflammation you notice after an injury, this kind of often is silent. You don't necessarily feel it, but over time, it begins damaging healthy tissues throughout the body, including your skin. Remember, your skin is constantly trying to repair itself. It's replacing millions of skin cells every day, producing new collagen, repairing damage from sunlight, maintaining a strong, healthier barrier. But chronic inflammation makes all of those jobs harder. It increases the breakdown of collagen.

• 2:53Dr. Mark Hyman?

  It interferes with your skin's natural repair process. It contributes to what we call oxidative stress, which damages healthy cells and accelerates visible signs of aging like wrinkles. Over time, that means of course more wrinkles. It means less elasticity. It means slower healing. And skin that simply doesn't look as vibrant as it once did. So where does all that inflammation come from? Well, for many people, it's not one thing. It's not one dramatic dead. It's accumulation of everyday habits. It's a diet high in ultra-processed foods. It's poor sleep. It's chronic stress. It's too little movement. Smoking. It's excess alcohol. Even unmanaged blood sugar. Each one adds a little more fuel to the fire and eventually, your skin starts reflecting

• 3:35Dr. Mark Hyman?

  on what's happening beneath the surface, which is why healthy skin isn't just about what you put on your body. It's also about what you put in your body. How well you sleep? How much you move? How well you manage stress? Every one of those choices influences inflammation. And inflammation influences how your skin ages. But inflammation isn't acting alone. It's another process that's going on that may be aging your skin every time you eat and has everything to do with your blood sugar, blood sugar and glycation. This is one of the biggest drivers of skin age that almost nobody talks about. And most people think high blood sugar is only a problem if you have diabetes, but long before someone develops diabetes, your pleaded blood sugar spikes can begin affecting tissues throughout the whole body, including your skin.

• 4:20Dr. Mark Hyman?

  And here's what happens. Every time you eat, your blood sugar naturally rises. That's normal. The problem comes when your blood sugar is elevated too often or it stays elevated for too long. Over time, some of that excess sugar begins sticking to proteins in your body, especially collagen. Scientists call these compounds AGES or advanced glycation end products, or AGES. And they live up to their name because they literally accelerate the aging process. Think of collagen like a brand-new rubber band. When you're, when you're young, it's flexible, it's strong, it's stretchy, it helps your skin bounce back. Now imagine putting that rubber band into a hot oven. It becomes stiff, brittle, much easier to crack. And that's a good way to think about what glycation does to collagen.

• 5:05Dr. Mark Hyman?

  It changes the structure of the protein itself. Instead of becoming flexible, it becomes rigid. Instead of repairing easily, it becomes more fragile. Result, less elasticity, more fine lines, more wrinkles in skin that doesn't bounce back the way it used to. And this isn't just happening inside your skin. The same exact process can affect your blood vessels, your eyes, your kidneys, even your brain, which is why I always say healthy skin is often a reflection of a healthy metabolism. Now, the good news is, this is something you have a tremendous amount of control over. Eating a diet rich in whole foods, building muscle, exercising regularly, sleeping well, and keeping your blood sugar steady. Well, it doesn't just support your heart or reduce your risk of diabetes.

• 5:46Dr. Mark Hyman?

  It also helps protect one of the proteins your skin depends on most, collagen. But collagen isn't simply something we protect. It's something your body is constantly rebuilding. One of the most fascinating repair systems in all of biology. It's called autophagy or autophagy, which means eating yourself. And one of the most fascinating discoveries in longevity science is this thing called autophagy. The word literally means self-eating. I know that sounds a little strange, but it actually is one of the smartest repair systems your body has. Think of every cell in your body as a home. Over time, things wear out, run out of your brakes, supplies that stop working, boxes pile up in the garage. If nobody ever cleans the house, well, eventually there's less and less room for the things that actually matter. Your cells face the same problem.

• 6:31Dr. Mark Hyman?

  Every day, they accumulate damaged proteins, worn-out mitochondria, broken cellular machinery. If all that debris simply piled up, your cells would become less efficient, less resilient, and over time, they would begin functioning like older cells. And that's where autophagy comes in. Think of it as your body's housekeeping and recycling department. It identifies damaged or dysfunctional parts inside the cells. It breaks them down and then salvages the useful parts, clears away what no longer serves you. And instead of letting this cellular junk accumulate, your body creates room for healthier, better functioning cells. It's one of the reasons scientists are so interested in autophagy as a hallmark of healthy aging because aging isn't just about getting older. It's also about gradual accumulation of cellular damage.

• 7:15Dr. Mark Hyman?

  And autophagy helps your body manage some of that damage. Now, let's be clear about something. Autophagy is not a magic switch. It doesn't suddenly erase wrinkles. It doesn't instantly tighten loose skin. It doesn't reverse decades of sun damage. Healthy skin still depends on collagen, healthy hormones, good nutrition, blood sugar control, and protecting your skin from ultraviolet light. But healthier cells are better equipped to repair themselves. And healthier repair over time can contribute to healthier aging, including healthier skin. Okay, so life isn't getting less stressful. Your calendar isn't suddenly going to clear up. The demands aren't going away. The real question is, how well is your body recovering from all of it? Because recovery isn't just about getting through the day. It's about how well your body bounces back from stress, how well you sleep, and how

• 8:00Dr. Mark Hyman?

  much energy you have left in the tank when life keeps asking for more. Most people don't notice their recovery is slipping until they hit a wall. But your body often leaves clues long before that happens with stress markers like cortisol and DHEAs. That's exactly why we built Function. Function gives you access to 160-plus lab tests annually that measure signals in your blood, including nutrients, liver health, inflammation, and hormones. You can also complete your health baseline with an annual MRI that helps you see organs, tissues, and other changes. Check your health at functionhealth.com/mark. And if you're one of the first 1,000 people this week, use the code MARK2026 for a $50 credit for your $365 a year membership. So naturally, the next question becomes, how do you support autophagy?

• 8:45Dr. Mark Hyman?

  The good news is, many of the same habits that support longevity appear to support healthy cellular renewal. Things like regular exercise, special resistance training, and interval training, periods of time between meals, and for some people, appropriately supervised fasting, getting up for restorative sleep, managing blood sugar, reducing chronic inflammation, eating a nutrient-dense diet that gives your cells the building blocks they need to repair themselves. Notice a pattern? These aren't expensive biohacks. They're the same habits that improve almost every aspect of health, which brings us something incredibly important because even if your cells are doing an amazing job repairing themselves, they still need the raw materials to rebuild. One of the most overlooked anti-aging tools has nothing to do with skincare at all.

• 9:29Dr. Mark Hyman?

  And that's where muscle comes in. This one surprises almost everyone. When people think about healthier skin, they usually think about collagen, they think about moisturizers, cosmetic procedures. But one of the best things you can do for your skin may actually be building muscle. Now, that might sound strange because muscle and skin seem like completely different things, but they're deeply connected. And here's why. For years, we thought that muscle's only job was helping us move. Today, we know that's not true. Muscle is actually one of the most important longevity organs in the body. It's metabolically active. It's hormonally active. Every time you use it, it sends powerful signals throughout your entire body. When you build muscle, you become insulin sensitive, you reduce chronic inflammation, improve your blood sugar, you support healthier hormone balance, and your muscles release

• 10:12Dr. Mark Hyman?

  compounds called myokines, these tiny chemical messengers that communicate with your brain, your immune system, and your bones, and many other organs throughout your body. Exercise isn't just changing your muscles. It's changing the conversation happening throughout your entire body. Muscle's also helping improve circulation. It's helping deliver oxygen and nutrients to tissues, including your skin. Perhaps most importantly, muscle provides a structural support underneath your skin.

• 10:39Dr. Mark Hyman?

  Think about what happens as we age. Beginning around 30, most of us gradually begin losing muscle if we don't actively work to preserve it. And that loss accelerates with each decade, especially after menopause. As the foundation underneath the skin becomes smaller, the skin has less support. And that's one reason skin can appear thinner, looser, less firm over time. Which brings us to one of the biggest questions I hear today. What about loose skin after weight loss? Well, especially now that millions of people are losing significant amounts of weight with GLP-1 medications. Here's what I want people to understand. Loose skin is complicated. It depends on your age, your genetics, how much weight you've lost, how quickly you lost it, whether you've been pregnant, how much sun damage your skin has accumulated over the years, and how much collagen and elastin your skin still has.

• 11:24Dr. Mark Hyman?

  So let's be realistic. No cream, no supplement, no fasting protocol, no single exercise can guarantee you won't have loose skin. But there are absolutely things you can do to improve your odds. First, if possible, lose weight at a sustainable pace. Second, prioritize protein. Your body needs amino acids to build collagen, to repair tissues, to preserve muscle. Third, strength train throughout your weight loss journey. This is one of the biggest mistakes I see. People become completely focused on losing fat. They forget about preserving muscle. The goal isn't just to make the number on the scale smaller. The goal is to improve your body composition, to lose fat while maintaining or even building muscle underneath. Because that's what supports a healthier metabolism.

• 12:07Dr. Mark Hyman?

  Greater strength, greater balance, more independence as you age, and yeah, healthier looking skin. So if you're trying to improve your skin, don't just think about what's happening on the surface. Think about the foundation underneath it. Because healthy skin, well, it's built on a healthy body. Which brings me to the number one thing, that you age your skin faster than almost anything else. Sun exposure. Now, before you think I'm about to tell you to avoid the sun completely, I'm definitely not. Sunlight is essential for life. It helps you regulate your circadian rhythm, support your mood, stimulates vitamin D production. And spending time outdoors has enormous benefits for overall health. The goal isn't avoiding the sun. It's avoiding chronic overexposure and sunburns.

• 12:47Dr. Mark Hyman?

  Because while moderate sun exposure can be healthy, years of chronic unprotected ultraviolet exposure tell a very different story. Ultraviolet penetrates the skin and creates oxidative stress. It damages DNA, it breaks down collagen, it degrades elastin, it leads to this uneven pigmentation, fine lines, wrinkles. And over time, skin loses strength and elasticity. In fact, dermatologists have a name for this. Photoaging. Because much of what we think as, quote, "normal aging" is actually the cumulative effect of decades of sun damage. The encouraging news is, this is one of the most preventable causes of skin aging. If I could recommend just one anti-aging product, it wouldn't be an expensive cream. It would be a good broad-spectrum sunscreen that you'll actually use every day.

• 13:31Dr. Mark Hyman?

  Think of sunscreen as protecting the collagen and the elastin that your body has worked so hard to build. Now, I know many people are concerned about the ingredients in conventional sunscreens, and I think it's a reasonable question to ask. The good news is there are many excellent options available today that use mineral ingredients like zinc oxide and are formulated to be general on both your body and the environment. And one resource I often use is the Environmental Working Group, or EWG. Each year, we publish a guide to sunscreens that reviews their products based on their ingredients, UV protection, other safety considerations. Great place to start if you're looking for a cleaner, environmentally conscious option. And remember, sunscreen is only one part of sun protection. A hat. Protective clothing. Seeking shade during the strongest midday sun.

• 14:16Dr. Mark Hyman?

  Those habits can go a long way toward protecting your skin for a lifetime. Because when you protect your skin today, you're protecting the collagen, the elastin, the healthy cells you're relying on for years to come. Okay, we've covered the biggest factors that determine how your skin ages, but I know that probably brings up a few questions. Questions like, should I take collagen? Can fasting actually tighten loose skin? Do expensive creams really work? Well, let's finish with a quick rapid-fire round. Does collagen powder work? It may modestly improve elasticity and hydration. Can fasting tighten loose skin? Not directly. Can expensive creams replace healthy habits? Absolutely not. Think of topical skincare as supporting the foundation, not replacing it. What's the best daily anti-aging skin routine?

• 15:00Dr. Mark Hyman?

  Lift weights, eat enough protein, control your blood sugar, protect your skin from the sun, sleep, the usual stuff. Here's what I hope you remember. Healthy skin is never just skin deep. It reflects the health of your metabolism, your hormones, your muscles, your nutrition, your sleep, your daily habits. And yes, a great skincare routine can help, but no cream can replace what happens inside your body. Every workout, every protein-rich meal, every good night's sleep, every time you keep your blood sugar steady, every time you protect your skin from the sun, you're investing in your skin's future. So stop asking, what's the best anti-aging cream? And start asking, how do I build healthier cells? Because healthy skin isn't something you buy. It's something you build.

• 15:44Dr. Mark Hyman?

  And when you build health from the inside out, your skin often becomes one of the first places the world notices. If you love this podcast, please share it with someone else you think would also enjoy it. You can find me on all social media channels at DrMarkHyman. Please reach out. I'd love to hear your comments and questions. Don't forget to rate, review, and subscribe to The Dr. Hyman Show wherever you get your podcasts. And don't forget to check out my YouTube channel at DrMarkHyman for video versions of this podcast and more. Thank you so much again for tuning in. We'll see you next time on The Dr. Hyman Show. This podcast is separate from my clinical practice at the Ultra Wellness Center, my work at Cleveland Clinic, and Function Health, where I am Chief Medical Officer. This podcast represents my opinions and my guests' opinions. Neither myself nor the podcast endorses the views or statements of my guests.

• 16:27Dr. Mark Hyman?

  This podcast is for educational purposes only and is not a substitute for professional care by a doctor or other qualified medical professional. This podcast is provided with the understanding that it does not constitute medical or other professional advice or services. If you're looking for help in your journey, please seek out a qualified medical practitioner. And if you're looking for a functional medicine practitioner, visit my clinic, the Ultra Wellness Center at UltraWellnessCenter.com, and request to become a patient. It's important to have someone in your corner who is a trained, licensed healthcare practitioner and can help you make changes, especially when it comes to your health. This podcast is free as part of my mission to bring practical ways of improving health to the public. So I'd like to express gratitude to sponsors that made today's podcast possible. Thanks so much again for listening.

• 17:12Dr. Mark Hyman?

  When it comes to supplements, you only want the best for your body, the kind with the highest quality, cleanest, and most potent ingredients you can get. That's exactly what you'll find at my supplement store, where I've hand-selected each and every product to meet the most rigorous standards for safety, purity, and effectiveness. These are the only supplements I recommend to my patients, and they're also what I use myself. Whether you want to optimize longevity or reduce your disease risk, or you're looking to improve your sleep, blood sugar, metabolism, gut health, you name it, DrHyman.com has the world's best selection of top-quality, premium supplements, all backed by science and expertly vetted by me, Dr. Mark Hyman. So check out DrHyman.com, because when it comes to your health, nothing less than the very best will do. That's DrHyman.com, D-R-H-Y-M-A-N dot com.