The Pill: Is It Messing Up Our Brain and Body?

For decades, taking the birth control pill to prevent pregnancy was seen as a no-brainer. But lately, people are saying that it’s actually a brain-changer. They say that the pill can affect who you’re attracted to, that it can tank your libido, and that it can make you depressed. Instead, some influencers are telling us to try an amazing, hormone-free method — where all you have to do is listen to your body. So … are they right?? We’re tackling these birth control claims and more, with psychologist Dr. Julia Stern, biologist Madita Zetzsche, neuroscientist Dr. Caitlin Taylor, and ob-gyn Dr. Jasmine Patel. This episode does mention depression. Here are some crisis hotlines: United States: US National Suicide Prevention Lifeline Dial 988 (Online chat available); US Crisis Text Line Text “HOME” to 741741 Australia: Lifeline 13 11 14 (Online chat available) Canada: Canadian Association for Suicide Prevention (See link for phone numbers listed by province) United Kingdom: Samaritans 116 123 (UK and ROI) Full list of international hotlines here Find our transcript here: https://bit.ly/ScienceVsThePill In this episode, we cover: (00:00) The Pill Under Fire (04:08) Does The Pill change who you’re attracted to? (13:00) Could The Pill turn off your ovulation scent? (18:59) How bad is The Pill for our sex drive and mental health? (21:10) Does The Pill really change your brain? (24:40) Does The Pill make you gain weight? (26:16) So how dangerous is The Pill — really? (27:10) Fertility Awareness Methods — are they too good to be true?? (31:32) Can pre-cum get you pregnant? Credits: This episode was produced by Rose Rimler, with help from Wendy Zukerman, along with Michelle Dang, Ekedi Fausther-Keeys, and Meryl Horn. We’re edited by Blythe Terrell. Fact checking by Eva Dasher. Recording assistance from Emile B Klein. Mix and sound design by Sam Bair. Music written by Bobby Lord, Bumi Hidaka, Peter Leonard, and Emma Munger. Thanks to all the researchers we spoke with for this episode, including Dr. Adriene Beltz, Prof. Alison Edelman, Dr. Emily Pfender, Prof. Jayashri Kulkarni, Dr. Jill Krapf, Dr. Rachel Urrutia, and Dr. Therese Johansson. Special thanks to Miah Foster. Science Vs is a Spotify Studios Original. Listen for free on Spotify or wherever you get your podcasts. Follow us and tap the bell for episode notifications. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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

• 0:01Wendy Zukerman?

  Hi, I'm Wendy Zukerman and you're listening to Science Versus.

• 0:05Wendy Zukerman?

  This is the show that pits facts against fallopian tubes. Today, we are tackling the pill.

• 0:18Wendy Zukerman?

  The pill burst onto the scene in the 1960s, and for tons of folks, it was seen as this wonderful thing. Country singer Loretta Lynn even wrote a song about how the pill was gonna open up all of these possibilities for women.

• 0:45Wendy Zukerman?

  This song was a hit, and the freedom that she's singing about, about choosing when to get pregnant and how many babies you're gonna have, it just resonated with loads of women. In fact, since the pill came out, women are more likely to go to college, become lawyers, judges, and doctors. Plus, the wage gap between men and women has narrowed by 30%. And some economists say that this is a direct result of the pill. But you fast forward to today, and for many, the pill has gone from hero to zero.

• 1:22Wendy Zukerman?

  People say that pumping ourselves with these hormones can be harmful.

• 1:26Speaker 01

  Birth control is one of the most damaging things you can put in your bodies.

• 1:30Wendy Zukerman?

  And that it can even change parts of our personality, like who you're attracted to, and also, who is attracted to you. Birth control can actually affect a woman's taste in men.

• 1:40Speaker 02

  We actually choose mates that are less compatible when we're on hormonal birth control. Is birth control ruining relationships, and people don't even realize it?

• 1:49Wendy Zukerman?

  We're hearing the pill can tank your mental health.

• 1:53Speaker 03

  I was the most depressed I've ever been. I didn't feel like me. I had no energy.

• 1:57Speaker 04

  Every morning I wake up and I just like struggle to get out of bed.

• 2:00Speaker 05

  And I couldn't get myself to not be mad. I was like not even in control of my own emotions, you know?

• 2:05Wendy Zukerman?

  Folks are even worried that the pill will mess with your brain.

• 2:09Speaker 05

  We're talking significant structural changes in the brain, in regions involving memory and emotional processing.

• 2:14Wendy Zukerman?

  And these ideas are huge right now. Even Elon Musk is worried about this.

• 2:19Speaker 06

  I think hormonal birth control is making a lot of women sad and depressed. Yes. And they don't realize it.

• 2:26Wendy Zukerman?

  Here he is talking to feminist icon Tucker Carlson in a video that's been watched millions of times, saying that women just don't understand how dangerous the pill is.

• 2:37Speaker 06

  Significant risk of depression, significant increase in suicide, and will make you want to go out with people that you don't actually like.

• 2:46Speaker 06

  That's actually true, by the way.

• 2:49Wendy Zukerman?

  And with all these concerns, some people are saying, "Bye-bye to the pill for good." It's time for me to come off the pill. A lot of my friends have gotten off of it. My sister's gotten off of it. I really don't know many people on it anymore. Now that I'm off it, literally, it is like night and day difference. Best decision I've ever made in my life.

• 3:11Wendy Zukerman?

  Today on the show, could the pill be changing us in these weird and even dangerous ways? And if you don't want to get knocked up, should you switch to something better? There's a lot of buzz about this exciting hormone-free, natural method that's out there. We're also going to get to the bottom of a question that we at Science vs. have had for half a decade, which is, can you really get pregnant from pre-cum?

• 3:41Wendy Zukerman?

  When it comes to the pill, there's at least one billionaire saying it'll...

• 3:45Speaker 06

  Make you want to go out with people that you don't actually like.

• 3:47Wendy Zukerman?

  But then, there's science.

• 3:52Wendy Zukerman?

  Science vs. the Pill is coming up just after the break.

• 4:01Wendy Zukerman?

  Get your business ready for clients faster with Base44. Describe what you need in your own words and build the website and software behind it. With database backend and hosting included. Go to base44.com. That's base44.com.

• 4:23Wendy Zukerman?

  Welcome back. Today, we're here to talk about the pill. And we are gonna do it with a real pill. Senior producer, Rose Rimla.

• 4:32Speaker 07

  Hi, Wendy.

• 4:33Wendy Zukerman?

  Hello. What made you want to do this episode?

• 4:36Speaker 07

  Well, I've just been seeing a lot of stuff online about how the pill isn't as safe as we thought it was and how it might be changing us. And those are very interesting claims to dig into. And they're also very relevant right now with all this uncertainty about access to contraception and abortion in the US. And you know, that's not the only reason people take the pill. But it still just seems like a really good time to dive into this.

• 4:58Wendy Zukerman?

  Yeah, for sure. I do think for a long time, there's just been this assumption that women are gonna go on the pill. You'll go on the pill, right? And so I think really questioning, what is it doing to us? I think is really important.

• 5:12Speaker 07

  Yeah.

• 5:12Wendy Zukerman?

  Okay, let's start with something that I've been seeing a lot of recently, but it's sort of been rolling around for years now. And it's this idea that the pill will change who you're attracted to, which is all part of this sort of larger idea that the pill, because of the way it affects hormones, it fundamentally changes who you are. So what do we know about this?

• 5:35Speaker 07

  I really enjoyed looking into this. So let's dive in. It's very interesting.

• 5:38Wendy Zukerman?

  Great.

• 5:39Speaker 07

  So this all comes from the fact that the combined pill, which is the typical birth control pill, stops you from ovulating. And that's how it works. That's how it keeps you from getting pregnant.

• 5:47Wendy Zukerman?

  Yeah, yeah.

• 5:48Speaker 07

  But ovulating is thought to be important for things like sexual attraction. So there's this theory out there that when you're ovulating, as in you're ready to make a baby, you're attracted to a different kind of guy than you are the rest of the month.

• 6:02Wendy Zukerman?

  Hmm.

• 6:03Speaker 07

  This theory predicts that if you're into guys, you would go for a more masculine kind of guy around that time.

• 6:08Speaker 05

  That's basically the idea.

• 6:10Speaker 07

  So I talked about this with Julia Stern. She's a psychologist at the University of Bremen in Germany.

• 6:15Speaker 05

  If you're fertile, you might be interested in a very masculine. Muscular guy and when you're not fertile anymore, you might be more interested in the good guy.

• 6:22Speaker 07

  So when you're in your fertile window, you are attracted to someone like Dwayne The Rock Johnson, but then when you're outside the fertile window, you're more like Timothy Chalamet kinda girl? Is that what's going on here?

• 6:37Speaker 05

  More or less, yes. So of course, Dwayne The Rock Johnson is like extremely muscular and has a very deep voice.

• 6:45Speaker 07

  Do you think those are appropriate celebrities to pick?

• 6:47Speaker 05

  I mean, Dwayne The Rock Johnson is pretty accurate, maybe, but what about Kevin James? For example, for the good guy?

• 6:55Speaker 07

  Oh.

• 6:56Speaker 05

  Wasn't he the king of queens actor?

• 6:59Speaker 07

  There's a meme that went around of him like shrugging, like shyly shrugging.

• 7:03Speaker 05

  Oh, yeah, but I know that meme.

• 7:05Speaker 07

  What are you seeing in this picture that makes you say, oh, yeah, that's it?

• 7:09Speaker 05

  Well, it's a smile, maybe, like this rather shy smile. He doesn't look dominant at all. It's more like, come home, I give you a hug.

• 7:18Speaker 07

  Uh huh. It's like, I'm not here to vanquish your enemies. I'm here to like, give you a nice hug and hand you a cup of tea at the end of the day.

• 7:24Speaker 05

  Yes, and then play with the children after coming home from work.

• 7:29Speaker 07

  Yeah, so I know that sounds like something totally made up on like, a dumb podcast.

• 7:36Wendy Zukerman?

  Not this one, not this one.

• 7:37Speaker 07

  Like a dumb podcast.

• 7:38Wendy Zukerman?

  Yeah, yeah.

• 7:40Speaker 07

  But scientists are like, into this idea.

• 7:44Wendy Zukerman?

  This idea that when you are ovulating, you're attracted to different kinds of men.

• 7:49Speaker 07

  Yeah, this is a real concept in the scientific literature. And the concern is that if you never ovulate, you never have that natural shift towards the rock. You're always, you're gonna be permanently stuck in the Kevin James portion of your cycle.

• 8:07Wendy Zukerman?

  I do have a bugbear with these evolutionary psychology theories, though.

• 8:12Speaker 07

  I know, you hate this stuff.

• 8:13Wendy Zukerman?

  I just, I mean, we know that these theories are based on these biases around what men and women are supposed to do. And these theorists could just say whatever they want. Has anyone actually tested this?

• 8:25Speaker 07

  Yeah, they show women pictures of men and they've altered the men's faces to be either more masculine or more feminine. That's pretty subtle. I can show you some of these.

• 8:37Wendy Zukerman?

  Yeah, you want to show me?

• 8:38Speaker 07

  Um, manipulated faces. So this is two different people. The image on the right has been masculinized. The image on the left has been feminized.

• 8:48Wendy Zukerman?

  I'm very good at playing, you know, that kid's game, spot the difference.

• 8:51Speaker 07

  Yeah.

• 8:52Wendy Zukerman?

  So this is really harnessing some of that power. The, the nose looks a little more pinched in the quote unquote feminized version.

• 8:59Speaker 07

  Yeah.

• 9:00Wendy Zukerman?

  The brow looks a little lower. The eyes look a little bigger in the feminized version.

• 9:06Speaker 07

  Yeah.

• 9:06Wendy Zukerman?

  Okay, so they give people, and they say, who are you more attracted to?

• 9:09Speaker 07

  Yeah, and a number of studies have actually found that women prefer a more masculine face around the time they ovulate and a less masculine face the rest of the month.

• 9:19Wendy Zukerman?

  Really?

• 9:20Speaker 07

  And women who are on the pill, studies have found that they always prefer the less masculine face.

• 9:27Wendy Zukerman?

  No.

• 9:28Speaker 07

  So these studies are all done in presumably straight cis women, by the way, and that's true for like all this research.

• 9:34Wendy Zukerman?

  Uh huh.

• 9:34Speaker 07

  So yeah, that's what a lot of studies have reported. And actually, a review paper that came out in 2014 said that the effect of birth control on mate choice is quote relatively robust.

• 9:44Wendy Zukerman?

  Relatively robust?

• 9:46Speaker 07

  That's what they said. And when I read that, I was like, oh, like, okay. And you know, the stakes are kind of big here because what this suggests is that if you're on birth control when you meet someone and then you go off it after you're married or vice versa, maybe you end up with someone who is not the partner you would have otherwise chosen.

• 10:06Wendy Zukerman?

  Hmm.

• 10:07Speaker 07

  And that is freaky. In fact, some data suggests that people who use hormonal birth control had 50% higher odds of getting divorced.

• 10:15Wendy Zukerman?

  Do you feel like who you're attracted to changes depending on where you are in your cycle?

• 10:22Speaker 07

  On the day? No. Julia doesn't either, actually, and that's one reason she wanted to get into this.

• 10:28Speaker 05

  I never experienced that. None of my friends has ever told me about that. But at the same time, sometimes in science, effects are really small and we are not really able to perceive them, but that kind of still happens unconsciously.

• 10:45Speaker 07

  So Julia looked at these studies more closely. And she realized something kind of odd in these studies.

• 10:54Wendy Zukerman?

  Mm hmm.

• 10:55Speaker 07

  And that is that in a lot of them, we really can't be sure that the women were definitely ovulating when they were tested.

• 11:02Wendy Zukerman?

  What?

• 11:03Speaker 07

  So most of these studies just estimated where people were in their cycle based on the date of their last period. So they just assumed like, okay, if you're on day 14, you're probably in your fertile window.

• 11:15Speaker 05

  But the reality is cycles vary a lot in length between women and also within women.

• 11:21Speaker 07

  It sounds like you're saying these studies were trying to figure out if women had a different preference when they were ovulating, but they didn't actually double check the women were actually ovulating. Is that true?

• 11:32Speaker 05

  Yeah, that's basically the point, yes.

• 11:35Speaker 07

  Sounds pretty bad.

• 11:37Wendy Zukerman?

  That is bad. Also, because it's so easy to check. I mean, now you can pay on a stick. Probably when these studies were done, you do a blood test.

• 11:46Speaker 07

  Yeah, I know. And so over the past decade or so, there have been all these studies that do actually check people's hormones and find out, okay, are you for sure ovulating? And then they get them to look at faces. And guess what, Wendy? These studies, they don't see this effect.

• 12:07Wendy Zukerman?

  Right. No, no, they don't. Of course they don't. I mean, you think, you think about how many bullshit studies came out that didn't actually test if women were ovulating? How many think pieces have been written about this evolutionary theory around masculine virile men and who's attracted to them? Oh, my God. But then what about the research that shows that people on the pill are always in the Kevin James portion of their cycle?

• 12:39Speaker 07

  That doesn't hold up either in newer studies, bigger studies. So there's this one big study that came out pretty recently. It was almost 6,500 people. They showed these faces to women on the pill versus not on the pill. No difference.

• 12:51Wendy Zukerman?

  No difference. Hmm, okay.

• 12:55Wendy Zukerman?

  So if you are on the pill and you are worried about this, you do not need to be worried about this. Based on all of your research, Rose, there is not good evidence that the pill changes who you're attracted to.

• 13:10Speaker 07

  That's what I would say, yeah. And can we just talk about the smell thing?

• 13:14Wendy Zukerman?

  The smell thing?

• 13:15Speaker 07

  Wendy, there is this idea that men can sniff out ovulating women and that they find them more attractive. And so therefore, men won't find you as attractive while you're on the pill.

• 13:29Wendy Zukerman?

  Okay. Um, had not heard this theory, but from an evolutionary perspective, I would actually buy it more than that masculine feminine garbage we just talked about.

• 13:44Speaker 07

  Why is that?

• 13:45Wendy Zukerman?

  Because it makes sense that for animals like humans who ovulate on a cycle every month, that there is some evolutionary pressure that has allowed males to sense when they might be fertile. Because, because it does take energy to blow your load. So you want to make sure you're putting it in the right place. So smell, sure.

• 14:10Speaker 07

  Yeah.

• 14:11Wendy Zukerman?

  Sure.

• 14:11Speaker 07

  I mean, that's interesting you you bring that up because like the a lot of the idea here is that a lot of animals display when they're ovulating, including other primates. So some of them have this like huge swelling of their anus and vulva when they're ovulating to be like, I am ovulating. Come and get me.

• 14:32Wendy Zukerman?

  I I just clenched, I just clenched.

• 14:35Speaker 07

  But then humans, we don't seem to. So we have what researchers call concealed ovulation. But then other researchers have been like, wait, maybe it's not really concealed. Maybe it's just very subtle. And so. They have actually done these studies to try to figure out, are there subtle little cues that men can pick up on that women like don't even know they're giving off?

• 14:58Wendy Zukerman?

  And that the pill is interfering with ultimately.

• 15:01Speaker 07

  And yes, and if that's so, then the pill could interfere with it.

• 15:04Wendy Zukerman?

  OK.

• 15:05Speaker 07

  And there's some very modern research on this. I spoke to someone who wanted to get to the bottom of that.

• 15:11Speaker 03

  Yes, so I'm Madita and I work at the University of Leipzig. I wanted to assess whether there is something in women's body odor that changes during the menstrual cycle.

• 15:26Speaker 07

  Madita Setcha, she wanted to actually do a chemical analysis of armpit odor over the course of the cycle.

• 15:34Wendy Zukerman?

  Yes.

• 15:34Speaker 07

  The idea here is to find out if the smell changes. And if so, can men tell? And then do they like it?

• 15:41Wendy Zukerman?

  This is great. This is great.

• 15:42Speaker 07

  So they recruited about 30 young women to come into the lab a bunch of times over the course of their menstrual cycle. And every time they came in, Madita's team sucked up a little bit of their BO with this special equipment.

• 15:57Speaker 03

  We have little metal tubes, basically like a straw.

• 16:02Speaker 07

  What did that look like? Well, you said straw. I'm imagining like you're on the other end like sucking it up. I'm sure that wasn't what it was.

• 16:07Speaker 03

  No, it was not the case, although it would have been exceptionally funny. No, but, um, no, we used a little pump.

• 16:16Wendy Zukerman?

  A little pump? So they're pumping out the sweat? It's not the sweat, it's the odor emitting from the armpits?

• 16:25Speaker 07

  Yes. This little machine would suck out the odor. And they were, they knew where the women were in their cycle. They gave them a pee test and a saliva test. Um, this is a good study.

• 16:38Wendy Zukerman?

  OK, so are we emitting some different odor when we're ovulating?

• 16:45Speaker 07

  Well, here's how Madita put it.

• 16:47Speaker 03

  There was no compound or a combination of compound which was indicative.

• 16:52Speaker 07

  Of, let's say, ovulation or the fertile window. That's a nerdy way of saying she couldn't find a smell. No, there's no ovulation scent. Ode ovulation is not a thing. No, I don't think that there is an ovulation scent in women so far.

• 17:14Speaker 07

  On top of that, Medita got guys to come into the lab as well and sniff BO samples from the armpits of the women throughout their cycle to see if the men's noses were more sensitive than her very sensitive chemical analysis. I guess so, yeah. And they couldn't tell. They didn't find the ovulation sweat any more attractive.

• 17:32Wendy Zukerman?

  So based on this idea that, you know, people blame the pill for covertly changing how you smell over your menstrual cycle and therefore men will find you less attractive. The fact that our scent does not change over our menstrual cycle suggests to me it's garbage. Like, the pill doesn't change your scent and therefore wouldn't make men more or less attracted to you because of that.

• 18:06Speaker 07

  Yeah, I think that's right. I agree with that. And so just to take it back to something we heard at the start of the show, I asked Julia about that Elon Musk line, saying like, this is true. If you take the pill, you end up with the wrong person.

• 18:20Wendy Zukerman?

  Right.

• 18:21Speaker 07

  And he said it will, quote, "make you go out with people you don't actually like." So what is your response to that?

• 18:27Speaker 05

  No one has ever provided any compelling evidence that this really happens.

• 18:34Speaker 07

  Even going back to that study that found that people who used hormonal birth control had 50% higher odds of getting divorced. Well, the same study found that you had 60% higher odds of getting divorced if you'd ever used condoms.

• 18:46Wendy Zukerman?

  Oh, so just using contraception makes it more likely you'll get a divorce?

• 18:52Speaker 07

  I mean, when you first said that, I didn't find it entirely convincing to be blaming the divorces on the pill. Something else is going on there. Yeah, I think what we could say from that study is like, whatever's driving people to divorce, it's not hormones.

• 19:11Speaker 07

  You know, in their contraception.

• 19:12Wendy Zukerman?

  Yeah, yeah.

• 19:14Speaker 07

  So Wendy, we've had ourselves a real nice little debunk fest.

• 19:17Wendy Zukerman?

  We have.

• 19:18Speaker 07

  But the pill is not totally innocent.

• 19:20Wendy Zukerman?

  Mm-hmm.

• 19:20Speaker 07

  So let's look at some of the stuff that does seem to happen.

• 19:23Wendy Zukerman?

  Okay.

• 19:24Speaker 07

  And let's start with libido. Because another potential consequence of not ovulating is that you could be less horny.

• 19:30Wendy Zukerman?

  Yes, right. And we know, based on science, real, actual science, that when you're ovulating, on average, you do get a little more horny, right? Which makes sense.

• 19:41Speaker 07

  Yeah. And so, you know, if you take that away, maybe that could tank your sex drive.

• 19:46Wendy Zukerman?

  Mm-hmm.

• 19:47Speaker 07

  And so to figure this out, there were researchers in Sweden that enrolled almost 350 women into a study and gave them either birth control pills or a placebo.

• 19:57Wendy Zukerman?

  Hmm, that sounds dangerous.

• 19:59Speaker 07

  They were told to use condoms or some other backup.

• 20:03Wendy Zukerman?

  Okay.

• 20:03Speaker 07

  So they didn't know if they were on the pill or not. And they got this survey about their sexual function, essentially, before they went on the pill and after they went on the pill, or placebo.

• 20:13Wendy Zukerman?

  Mm-hmm.

• 20:14Speaker 07

  And it turned out that, on average, people's sexual desire, arousal, and pleasure went down over the course of the study, so over three months.

• 20:22Wendy Zukerman?

  Mm-hmm.

• 20:23Speaker 07

  And this is a weird way to think about something like desire, but the amount of the decrease was like 7% or 8% of a decrease.

• 20:29Wendy Zukerman?

  So it's not necessarily going to tank your sex drive. But still, I mean, that is something to think about. Because this was an average, right? So it would have affected some folks more than others.

• 20:39Speaker 07

  Yeah, of cour-- yeah, for sure. And we don't know exactly why this happens. It could be the ovulating thing, but also, bigger picture, there is this sort of package of mental health effects that a lot of people say they experience when they take the pill.

• 20:54Wendy Zukerman?

  Mm-hmm.

• 20:54Speaker 07

  They say that the pill has actually been harmful to their mental health. And the same research actually gives us some clues about that. Because these women were also given surveys about their mood.

• 21:03Wendy Zukerman?

  Mm-hmm. So what did they find?

• 21:05Speaker 07

  So these women also scored worse on stuff like feelings of well-being, vitality, and self-control, interestingly.

• 21:14Speaker 07

  And other studies that track people who take the pill do find an increase in depression. And in clinical trials, four to 10% of people who went on the pill develop symptoms of depression.

• 21:25Wendy Zukerman?

  And what do we know about the mechanism here? Because on TikTok videos, you see people sort of combining this fact that the pill can increase your risk of depression with these headlines. You also see that the pill changes your brain.

• 21:41Speaker 07

  So there are studies that have found structural changes in the brain in people who are on hormonal birth control. And these are studies where they put someone in an MRI. They'll see sometimes that on the pill, areas of the brain are smaller or thinner. One study actually found that a person's cerebral cortex shrank after being on the pill. So you could see why people, you know, link this kind of stuff to what's causing depression.

• 22:09Wendy Zukerman?

  Yeah.

• 22:09Speaker 07

  But Caitlin Taylor, who's a neuroscientist at the University of California, Santa Barbara, she says that this is not the right interpretation here. And she pointed out that changes to the brain are not necessarily bad.

• 22:23Speaker 01

  You learn a new skill. It affects your brain. You live in an urban versus a rural environment. It affects your brain. Like, everything, that's why we're so successful. Our brain is malleable.

• 22:35Speaker 07

  Even studies that find a shrinking of the brain are not necessarily a concern because we know that the brain often shrinks in order to re-sculpt itself.

• 22:44Wendy Zukerman?

  Right.

• 22:44Speaker 07

  Especially when we're younger. So, for example, kids, studies have found that they actually lose gray matter as they learn. And in fact, more gray matter loss is associated with better test scores and even higher IQs. Even putting that aside, not every study finds brain shrinkage happens on the pill. Like, there are some studies that have showed the opposite, that women had increased gray matter on the pill compared with women not on the pill. So I think we have enough compelling evidence that it is having an effect on your body and your brain. But the nature of that effect, I think we're still wrapping our heads around. We're kind of the scientists.

• 23:24Wendy Zukerman?

  In the dark, trying to feel the elephant, or it's like, it's a trunk. No, it's a snake. Like, we're kind of coming together to try and be like, what is it that we're figuring out here?

• 23:38Wendy Zukerman?

  So it sounds like pinning the depression mechanism on changes in the brain is not a good idea because we're still working out what these changes mean at all.

• 23:47Speaker 07

  Yeah. And what's maybe surprising is that some people's mental health gets better on the pill. So it's a mixed bag. And we think the mechanism probably has more to do with... Well, we know there's tons of receptors for these hormones in the brain, that they interact with neurotransmitters like serotonin.

• 24:05Wendy Zukerman?

  So when you take these hormones in the pill, estrogen, progesterone, it can interact with these neurotransmitters in our brain.

• 24:13Speaker 07

  Yeah.

• 24:14Wendy Zukerman?

  And it's more likely that's to blame for increasing our risk of depression than the pill changing your brain.

• 24:21Speaker 07

  Yeah.

• 24:24Wendy Zukerman?

  After the break, does the pill make you put on weight? Plus, get excited because we are gonna go on a magical journey into the world of pre-cum.

• 24:38Wendy Zukerman?

  That's pre-cumming up.

• 24:55Wendy Zukerman?

  Welcome back. Today on the show, The Pill. So far, we've learnt that you should not trust Elon Musk when he tells you that birth control is gonna make you attracted to people that you otherwise would not be attracted to. And now, let's talk about weight gain.

• 25:14Speaker 07

  Yeah. And belief that the pill makes you gain weight is... This is important to talk about because it's a very common reason that people avoid taking the pill or stop taking it.

• 25:23Wendy Zukerman?

  Hmm.

• 25:23Speaker 07

  And there are, you know, potential mechanisms here, like why this might be happening. So one idea here is that maybe the pill, something about the hormones in the pill, cause your metabolism to slow down.

• 25:34Wendy Zukerman?

  Mm-hmm.

• 25:35Speaker 07

  And so researchers have actually tested this in monkeys. They gave monkeys in a lab a birth control pill every day for eight months. They also measured their metabolism before going on the pill and after. And because these were monkeys in a lab, they were able to keep their food the same. So if there was any weight gain, they could be confident it was because of a change in their metabolism.

• 25:58Wendy Zukerman?

  So what did they find?

• 26:00Speaker 07

  They actually lost weight.

• 26:01Wendy Zukerman?

  The monkeys lost weight?

• 26:02Speaker 07

  They didn't gain weight, they lost weight, which suggests that their metabolism increased slightly.

• 26:07Wendy Zukerman?

  Yeah.

• 26:08Speaker 07

  And we know that they lost fat, not muscle. And then from the studies that we have in people, well, they don't find that people lose weight on the pill. They also don't find that they gain weight either in comparison to, you know, like some kind of control group.

• 26:22Wendy Zukerman?

  Interesting. So another pill myth busted. The pill does not cause weight gain.

• 26:30Speaker 07

  That's right. And let me just bring up another thing that drives me kind of crazy, which is all this chatter about how dangerous the pill is and how many side effects it has. You know, a lot of what people point to is stuff that's either really rare or it's not even confirmed to be linked to the pill. And in reality, most researchers in this space agree that there's basically two major risks from the pill the average person should know about.

• 26:56Wendy Zukerman?

  Okay.

• 26:56Speaker 07

  And again, we're talking about the combined pill.

• 26:58Wendy Zukerman?

  Okay.

• 26:59Speaker 07

  So one is blood clots. Your risk will go from maybe three in 10,000 to maybe six in 10,000, once you're on the pill. And the other is breast cancer. And the risk for that goes from like five or six in 10,000 to about seven in 10,000.

• 27:15Wendy Zukerman?

  So small increases we're talking.

• 27:17Speaker 07

  Yeah. And also, you know, the pill will actually reduce your risk of some other cancers. So namely endometrial cancer and ovarian cancer.

• 27:25Wendy Zukerman?

  So Rose, we've gone deep on some myths and not so myths around the pill. But the pill is not the only game in town here. If you are a vagina and you're looking to have sex with a penis and you don't want to get pregnant.

• 27:39Speaker 07

  Yeah, of course, there are other options. But there's one in particular that I want to zoom in on because it's gotten a lot of attention online. And people are saying it's this great alternative. It's a revolutionary new way to manage your fertility.

• 27:51Wendy Zukerman?

  Oh.

• 27:52Speaker 03

  This is called the fertility awareness method, and all it requires of you is to take time to listen to your body. Zero hormones. That is also 99, over 99% effective when used perfectly.

• 28:04Speaker 07

  Fertility awareness? Listen to your body? This isn't new. It's kind of the oldest game in town, actually. So for those unfamiliar, break it down for us. So in a nutshell, this idea is that if you have a 28-day cycle, day one being your period, then day 14 is roughly when you ovulate. And so you would avoid having unprotected sex in the days just right around that time. And if you're just looking at a calendar to do this, studies have shown that the failure rate here can be as high as 25%.

• 28:36Wendy Zukerman?

  Oh, if you don't want to get pregnant, that is not a successful, no, that's not good at all.

• 28:42Speaker 07

  Not great. And this could be because it's just not a great way to pick up ovulation. Like we talked about with the study on masculine and feminine faces. There's too much variation in the average person's cycle. Yeah, that's why those studies were so bad, right? Exactly. But to be fair to the TikTokers, they're often talking about adding other observations to make this method more successful. Things like looking at your cervical mucus, as I like to call it, the gunk in your underwear.

• 29:14Speaker 07

  I talked about this with Jasmine Patel. She's an OB-GYN at the University of California, Irvine.

• 29:19Speaker 03

  The day before and the day of ovulation, your cervical mucus becomes very slippery, kind of acting as additional lubricant. Your body's trying to have you have sex so that you get pregnant.

• 29:31Speaker 07

  So if you're like looking down and you're producing your own lube, that's an indication that you might be ovulating?

• 29:36Speaker 03

  Exactly.

• 29:38Speaker 07

  It's a little bit more involved than just looking at your dirty panties. A lot of experts recommend putting a couple of fingers in your vagina and then checking the texture of what comes out. When you're ovulating, it's kind of like egg whites. Okay. You could also use those pee strips that we mentioned earlier that check hormones to see if you're ovulating. And there's another method where you track your temperature by taking it first thing in the morning with a very sensitive thermometer.

• 30:00Speaker 03

  And so when you ovulate, it goes about 4/10 of a degree up compared to baseline. Very specific.

• 30:08Speaker 07

  So there are all these different formulas and apps for putting this data together in order to guess when you're about to ovulate. Okay. Which means like this is the time when you can get pregnant. Yeah, yeah. And so if you do this perfectly... These methods can be up to 99.6% effective.

• 30:27Wendy Zukerman?

  Wow. 99.6, that puts it up with the pill, right?

• 30:33Speaker 07

  That's about the same as perfect use of the pill. Yeah.

• 30:36Wendy Zukerman?

  Huh. So would you use this?

• 30:40Speaker 07

  Ah, you know, I was really surprised that this could be so effective and that the TikTokers are kind of right here, like, oh, there is a fertility awareness method that can be 99% effective.

• 30:52Wendy Zukerman?

  Yeah.

• 30:52Speaker 07

  Um, that's really cool. But I'm still kind of like uncomfortable with how this gets tossed around on TikTok because, you know, we only have a few studies really on these methods. While for the pill, we have tons of studies and many thousands of people and all these different circumstances, so we can just be much more confident about the effectiveness there. And then also, you know, these methods take a lot of work and a lot of careful planning. You got to think about this, track it every day. And Jasmine says it's not always smooth sailing.

• 31:24Speaker 03

  It also entails like knowing your body really well and having your body not change because of stress or because of a fever or because of a vaginal infection.

• 31:33Wendy Zukerman?

  So fertility awareness methods, they are an option and they're not a bad option, but be aware that just like condoms, they can have holes in them.

• 31:45Speaker 07

  Yes.

• 31:46Wendy Zukerman?

  Okay, so while we're talking about condoms, let's talk about the fetus in this equation here.

• 31:53Speaker 07

  Yes. We don't have hormonal birth control for them yet, but there are non-hormonal options. Obviously, they could wear condoms.

• 32:03Wendy Zukerman?

  Yes.

• 32:03Speaker 07

  Could get vasectomies. They could also not ejaculate in the vagina, right? They could pull out.

• 32:08Wendy Zukerman?

  Pull out method. But I guess there has always been this question of can you get pregnant from pre-cum?

• 32:16Speaker 07

  Right. A classic.

• 32:18Wendy Zukerman?

  Which we have been tantalizing the audience with the answer of this question for probably half an hour now.

• 32:28Wendy Zukerman?

  All right. If it's not obvious, the scientific question around the pull-out method, which has been circling around the Science vs. Office for some time, is that you're having sex, you're the penis, and a little bit of pre-cum is coming out into the vagina. But yet then, when you're about to truly blow your load, you pull out, out it goes.

• 32:52Speaker 07

  Yeah, that's how it works.

• 32:53Wendy Zukerman?

  And, you know, you watch American Pie and movies of that vintage. They'll talk about this fear of pre-cum. But scientifically, we didn't know if there was enough sperm, good sperm, in pre-cum to make someone pregnant.

• 33:10Speaker 07

  Yeah.

• 33:13Wendy Zukerman?

  So what do we know now, Rose?

• 33:16Speaker 07

  We have new research on this. It just came out.

• 33:19Wendy Zukerman?

  Wow, hot off the pre-cum press.

• 33:22Speaker 07

  Yes, and it's from Jasmine. So she did this great study about looking for swimmers in pre-cum. She got men to come to a clinic.

• 33:31Wendy Zukerman?

  I thought she just got men to come.

• 33:38Speaker 07

  They came into the clinic, like, leaving no pods at all.

• 33:43Wendy Zukerman?

  Okay.

• 33:44Speaker 07

  And to masturbate, kind of to give a sperm sample, but doing it a little differently than how you might otherwise give a sperm sample.

• 33:53Wendy Zukerman?

  Right.

• 33:54Speaker 07

  So to collect the pre-cum, she basically had the guys masturbate into a Petri dish. So the guys had to press the tip of their penis onto the Petri dish as they jerked off.

• 34:07Wendy Zukerman?

  They'd have to be experienced jerkers for that.

• 34:12Speaker 07

  I think we can assume they were experienced jerkers.

• 34:17Speaker 07

  That's a fair assumption. So then the dribble, or whatever was coming off the penis before ejaculation, could kind of just spread across the dish without losing a drop?

• 34:29Speaker 03

  Yeah, and so it just depends on how much that person was producing, right? So some people will produce a larger volume, and so it'll come out in a larger quantity, and therefore have more propulsion and, you know, actually get onto the dish.

• 34:41Speaker 07

  Okay.

• 34:41Speaker 03

  And for others that only produce a few drops, in order to transfer it, like, you need to kind of push it onto a container. And so that's when they had to push their penis against the dish to be able to transfer it, so we're not losing any specimen.

• 34:55Wendy Zukerman?

  So what happened next?

• 34:56Speaker 07

  Well, what happens next is the men come, but they pull their penis off the dish and into a cup. So what she was looking for was, do the men have at least a million healthy swimmers per milliliter? That's what scientists think that you need to get someone pregnant.

• 35:10Wendy Zukerman?

  Okay.

• 35:11Speaker 03

  What we found was that there were very, very few samples that had motile sperm greater than 1 million sperm per milliliter.

• 35:21Wendy Zukerman?

  Mm-hmm.

• 35:22Speaker 03

  The majority of people had no sperm in their pre-ejaculate whatsoever.

• 35:28Speaker 07

  Interesting, right?

• 35:28Wendy Zukerman?

  Very.

• 35:29Speaker 07

  But here's the catch.

• 35:31Speaker 03

  It wasn't consistent. So the same person could sometimes have sperm of high quantities in their pre-ejaculate, and sometimes not have it, meaning that sometimes they're at higher risk of pregnancy, and sometimes they're not.

• 35:44Wendy Zukerman?

  Oh, that's annoying, because if you're having sex with a penis, or if you are the penis, you don't know if you're a sperm-filled precum have a or not.

• 35:55Speaker 07

  Yeah. Ultimately, out of 24 people in Jasmine's study, five sometimes had enough sperm in their precum to get someone pregnant.

• 36:03Wendy Zukerman?

  Uh-huh, five out of 24. I mean, that's enough to make me a little worried, I've got to say.

• 36:10Speaker 07

  Yeah, I don't know, but it depends. Like, I think some people see the precum as half-full, and some people see the precum as half-empty.

• 36:19Speaker 07

  You mean, you can look at it, it's, you know, the thing with birth control, and here's something that has like really been driven home to me as I'm, as I've been working on this episode is like, everybody's risk tolerance is different.

• 36:27Wendy Zukerman?

  Yeah, that's, of course, of course. And I think, I mean, what, what I do really like, I guess, about this new conversation around the pill is because for so long, there really has been this just assumption that, that women and folks with vaginas are gonna be taking it. And for some people, as you've talked about, there are side effects. They, it does affect their mental health. It, uh, it may lower their libido and there are those, you know, very, um, rare risks around breast cancer and blood clots. And so it is right to ask yourself, you know, if you're starting to have P and V sex, is this right for you? And if not, what else is out there?

• 37:08Wendy Zukerman?

  And can we start putting a little pressure and responsibility on the penis in the equation? So for that reason, it's great.

• 37:15Speaker 07

  Yeah, I agree. But I do think that they can go overboard with that messaging. Because what online creators are trying to do is to get your attention. And so saying that the pill is dangerous, there's a marvelous new method, that's perfect. Saying all that stuff, uh, gets eyeballs. It's not about responsible communication about reproductive health.

• 37:44Wendy Zukerman?

  But that's what you come to Science Versus for. Responsible communication about reproductive health and the real science on precome.

• 37:56Speaker 07

  We always find the important and meaningful stories to bring to you, our beloved audience.

• 38:04Wendy Zukerman?

  And that is Science Versus. Um, Rose, how many citations are in this week's episode?

• 38:11Speaker 07

  Uh, this week, we have 75 citations.

• 38:13Wendy Zukerman?

  Seventy-five. And if people want to see more, learn more about the pill, where do they find these citations?

• 38:20Speaker 07

  They can check the transcript, and there is a link to the transcript in our show notes.

• 38:24Wendy Zukerman?

  And on social media this week, anything fun?

• 38:27Speaker 07

  We're gonna put some pictures of the masculine or feminized male faces, so the listeners can play, spot the difference too. And, um, we could throw in a picture of a chimpanzee in heat.

• 38:39Wendy Zukerman?

  Please, yeah.

• 38:41Speaker 07

  Okay, all right, I'll make that happen.

• 38:43Wendy Zukerman?

  Our Instagram is science underscore V S. And my TikTok is at Wendy Zukerman, so come say hello.

• 38:51Speaker 07

  All right, thanks so much, Rose.

• 38:52Wendy Zukerman?

  Thanks, Wendy.

• 38:59Wendy Zukerman?

  This episode was produced by Rose Rimler with help from me, Wendy Zukerman, along with Michelle Dang, Aketi Foster-Keez, and Merrill Horne. We're edited by Blythe Terrell. Fact checking by Eva Dasha. Recording assistance from Emil B. Klein. Mix and sound design by Sam Behr. Music written by Bobby Lord, Bumi Hidaka, Peter Leonard, and Emma Munga. Thanks to all of the researchers that we spoke to for this episode, including Dr. Adrian Belt, Professor Alison Edelman, Dr. Emily Fender, Professor Jayshree Kulcarni, Dr. Jill Kraft, Dr. Rachel Urrutia, and Dr. Therese Johansson. Special thanks to Maya Foster. Science Versus is a Spotify Studios original. Listen to us for free on Spotify or wherever you get your podcasts. We are everywhere.

• 39:42Wendy Zukerman?

  But if you are listening on Spotify, then tap the bell icon so you get notifications when new episodes come up. And also, if you like the show, please rate us. Give us a five star review. It helps people find the show. Thank you so much for listening. I'm Wendy Zukerman. Fact you next time.