The Full Moon: Is It Messing With Us?

People swear that weird stuff goes down on a full moon. In fact, even SERIOUS folks like the nerds who work in ERs will tell you that something is off about those nights. And what’s amazing is that science has actually looked at this. And … there is some weird stuff here! From animals to ERs to our circadian rhythms to our menstrual cycles, we’ll find out — is something afoot during a full moon? We talk to Emeritus Prof. of emergency medicine Dr. Wendy Coates and circadian rhythm researchers Prof. Horacio de la Iglesia, Prof. Kristin Teßmar-Raible, and Prof. Charlotte Helfrich-Förster. Find our transcript here: https://bit.ly/ScienceVsFullMoon In this episode, we cover: (00:00) What do people think the full moon is doing to us? (03:54) How the moon influences animals (07:47) Does the full moon make ERs busier? (15:09) Does the full moon affect our sleep? (22:11) HOW is the full moon messing with us? (31:05) Does the full moon affect our menstrual cycles? This episode was produced by Meryl Horn, with help from Wendy Zukerman, Rose Rimler, Michelle Dang, and Ekedi Fausther-Keeys. We’re edited by Blythe Terrell. Mix and sound design by Bumi Hidaka. Fact checking by Marlowe Starling. Music written by Bumi Hidaka, Bobby Lord, Emma Munger, So Wylie, and Peter Leonard. Thanks to all the researchers we spoke to for this episode, including Dr. Ron Flick, Dr. Michael Smolensky, Michael Bevington, Dr. Laurel Symes, Professor Laura Prugh, and Dr. Maarten Nijsten. Special thanks to Kevin Walsh and all the folks who chatted with me about the full moon. 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.

• 0:00Wendy Zukerman?

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

• 0:05Wendy Zukerman?

  This is the show that pits facts against the full moon. Does it change who we are?

• 0:13Wendy Zukerman?

  This episode about the full moon has been one of our most requested episodes this past year. You asked for it, so here it is.

• 0:27Wendy Zukerman?

  And to start our journey, we sent senior producer Meryl Horn out to brave the streets of New York City. Picture it. There's a chill in the air. Out in the east, the full moon was on the rise. And she ventured into a park to hear firsthand what people experience when there's a full moon.

• 0:48Speaker 01

  Makes people wild. It makes them carnal. There's a carnal thing happening.

• 0:53Speaker 02

  Everyone does not act right. It's terrible.

• 0:55Speaker 03

  I think people are just wilding out. Caws out, you know?

• 0:58Speaker 04

  I'm blaming the moon. Bad damn moon.

• 1:01Wendy Zukerman?

  Some people said that the full moon stirred up all this drama in their lives. One guy said that sometimes he doesn't even go out when there's a full moon.

• 1:09Speaker 05

  I'm gonna stay in that night. I'm gonna play it safe, just like, cause I know I could feel weird or do crazy stuff.

• 1:16Wendy Zukerman?

  Folks said you just knew it was gonna be a full moon that night. Because people at work would be going bonkers. And this is in the research, too. It shows that some healthcare workers think the full moon makes their patients behave stranger. One survey even showed that some doctors and nurses think they should get full moon hazard pay. Meryl heard about this as well at the park.

• 1:41Speaker 06

  My mom was a nurse at the state hospital. And she had a lot of psychiatric patients. And she was like, oh, man, the full moon is the worst. It's the absolute worst. So maybe it is. Because people do act crazy.

• 1:54Speaker 02

  I've worked in retail. I worked there for like a full year, every single time, on the full moon. We had the craziest customers. And I would tell everyone, I'd be like, it's the full moon. Watch out. And they'd be like, it's not gonna be that bad of a day. It was. It was the worst days, every single day. No, I quit. I quit on the full moon, actually. Like, fully quit on the full moon.

• 2:14Wendy Zukerman?

  And perhaps the creepiest thing of all, people said that the full moon could make blood come out of your vagina. I mean, they didn't put it quite like that.

• 2:25Speaker 03

  It definitely affects me from like the feminine cycle, the monthly cycle.

• 2:31Speaker 07

  Do you think you sync up with the full moon?

• 2:33Speaker 03

  Yeah, for sure.

• 2:34Speaker 02

  My period will probably be coming because it's usually cycled with the moon. Literally, I go to beauty school, I go to cosmology school, it's mostly women. All their cycles synced up to this week, basically. So up to the full moon. So like, they're in the middle of their periods, literally today.

• 2:50Wendy Zukerman?

  So could the moon be affecting our body and our behavior in these strange ways? While this idea might sound like it belongs in the world of horoscopes, perhaps even fairy tales, some scientists have been taking it very seriously. And in the past few years in particular, there's been a slew of peer-reviewed scientific papers coming out and claiming that the moon really can affect our bodies in very surprising ways.

• 3:23Wendy Zukerman?

  So in today's episode, we are going to look at this cutting-edge science. And by the end of the app, you might just be feeling a little carnal yourself.

• 3:34Wendy Zukerman?

  For hundreds of years, we've blamed all sorts of stuff on the...

• 3:37Speaker 02

  Bad damn moon.

• 3:39Wendy Zukerman?

  But then, there's science.

• 3:42Wendy Zukerman?

  Science vs. the Full Moon is coming up after the break.

• 3:52Speaker 06

  Are you looking for support in your weight management journey? ZepBound Terzepatide may be able to help. ZepBound is a prescription medicine used with a reduced calorie diet and increased physical activity to help adults with obesity, or some adults with overweight who also have weight-related medical problems to lose excess body weight and keep the weight off. ZepBound is approved as a 2.5, 5, 7.5, 10, 12.5, or 15-milligram injection. ZepBound contains Terzepatide and should not be used with other Terzepatide-containing products.

• 4:25Wendy Zukerman?

  Or any GLP-1 receptor agonist medicines. It is not known if Zepbound is safe and effective for use in children. Don't share needles or pens or reuse needles. Don't take if allergic to it. Or if you or someone in your family had medullary thyroid cancer. Or if you've had multiple endocrine neoplasia syndrome type two. Tell your doctor if you get a lump or swelling in your neck. Stop Zepbound and call your doctor if you have severe stomach pain or a serious allergic reaction. Severe side effects may include inflamed pancreas or gallbladder problems. Tell your doctor if you experience vision changes before scheduled procedures with anesthesia. If you're nursing, pregnant, plan to be, or taking birth control pills. Taking Zepbound with a sulfonelurea or insulin may cause low blood sugar. Side effects include nausea, diarrhea, and vomiting,

• 5:09Wendy Zukerman?

  which can cause dehydration and worsen kidney problems. Talk to your doctor. Call 1-800-545-5979 or visit zepboundslily.com.

• 5:22Wendy Zukerman?

  This episode is brought to you by Chase Sapphire Reserve. On this podcast, we sort fact from fiction. So here's a quick truth for you. With Sapphire Reserve, you can spend all around the world. Not only that, but you can earn four times the points on flights and hotels, book direct, and three times the points on dining. Plus, enjoy access to award-winning airport lounges and exclusive restaurant tables. Learn more at chase.com/sapphirereserve. Cards issued by JP Morgan Chase Bank and a member FDIC. Subject to credit approval. Terms apply.

• 6:03Wendy Zukerman?

  Welcome back. Today on the show, we're looking at the full moon. There's one coming up on Monday. And so we're asking, can it really influence us, change our behaviour? And fellow lunar explorer, Merrill Hahn is here.

• 6:19Speaker 07

  Hi, Wendy.

• 6:20Wendy Zukerman?

  OK, so first up, can we just get a bit of a lay of the land? And could you just explain, why do you see a full moon? Or a half moon or whatever? Why does it change?

• 6:34Speaker 07

  Yes, I can explain this. I actually brought a prop.

• 6:38Wendy Zukerman?

  Oh. Great.

• 6:40Speaker 07

  Okay, so I have like a model of

• 6:42Wendy Zukerman?

  Wow.

• 6:43Speaker 07

  the Earth and the moon for you.

• 6:45Wendy Zukerman?

  My god, you've really gone all out, Meryl.

• 6:49Speaker 07

  Okay, so we are, right now, on the surface of the Earth, right?

• 6:54Wendy Zukerman?

  Yeah, that I know. Yes.

• 6:56Speaker 07

  So imagine you're spinning around and around, the Earth is moving around and around. And when we are on the part of the Earth that's facing away from the Sun, that's what we call nighttime, right?

• 7:09Wendy Zukerman?

  Right, yes.

• 7:10Speaker 07

  Well, the moon also has a side that's lit up and a side that's dark. And we see different amounts of that lit up side depending on where the moon is in its orbit around the Sun. So when we see a full moon, it's when the moon is in this really particular position, where you've got the moon on one side of the Earth and then the Sun like on the other side. So it's almost like the Sun and the moon are making an Earth sandwich.

• 7:40Wendy Zukerman?

  Okay, and the Earth is in the middle, it's the meat, cheese of the sandwich.

• 7:46Speaker 07

  Yeah, and so the new moon, when the moon looks dark, is when it's in a different position. So in that case, the moon is like the meat of the sandwich and the Earth and the Sun are the bread.

• 8:00Wendy Zukerman?

  Okay, so could it, could just that fact, that the billiard balls up in space are in this arrangement, affect our behavior?

• 8:12Speaker 07

  I mean, it feels like maybe far-fetched at first, but if you think about it, we know that the moon affects other animals.

• 8:20Wendy Zukerman?

  That's right.

• 8:22Speaker 07

  And you know, it's funny, the one thing that everybody associates with the full moon, wolves howling, I actually couldn't find any evidence backing that up at all.

• 8:31Wendy Zukerman?

  Oh, okay.

• 8:33Speaker 07

  But what I do have for you is that coyotes will howl more together on a new moon night.

• 8:42Wendy Zukerman?

  That's what they sound like?

• 8:44Speaker 07

  Yeah, kind of even creepier, right? Like, there are these coyotes that will like yip together in groups at the darkest time of the month. Some owls will call out more when the moon is darker. And badgers will pee more on stuff during a new moon.

• 9:00Wendy Zukerman?

  But what about, wait, who's affected by the full moon?

• 9:04Speaker 07

  I'm getting there.

• 9:04Wendy Zukerman?

  Meryl, the episode is called Full Moon, not New Moon.

• 9:08Speaker 07

  All right, and then on full moon, some birds will hatch more around a full moon. There's a, there's a little worm that does a mating dance that happens just after a full moon. Corals release their spawns a few nights after a full moon, which is an incredible event that you can see from space. And some primates, like nocturnal ones, will eat more during full moons. And I even found this one reference from the 1800s where a scientist said that rhesus monkeys were at their most fertile during full moons. So there are like all these ways that the moon is affecting animals.

• 9:48Wendy Zukerman?

  Now we're cooking with the rhesus monkeys. We're in primate land. I feel a kinship. All right, but what about human animals? Meryl, are we affected by the moon? And why don't we start with the idea that on a full moon, hospitals get packed, patients are going wild.

• 10:07Speaker 07

  Yeah, yeah, so researchers have actually looked into this. So there is, you know, the thinking is that if the full moon really is making people act more recklessly, then maybe we'll like see evidence for that in how busy ERs are. And, I mean, there is just a long history of people thinking that this kind of thing is true. You can see it in our language, like the word lunatic that comes from the moon.

• 10:31Wendy Zukerman?

  Right.

• 10:32Speaker 07

  And so to find out if this is real, I talked to another Wendy, Wendy Coats. Is that going to be confusing for you?

• 10:39Wendy Zukerman?

  No, it'll make me feel right at home.

• 10:43Wendy Zukerman?

  So what does expert Wendy say?

• 10:44Speaker 07

  Well, she's been an emergency medicine physician for over three decades, and she published one of the first studies on this question of whether ERs are more busy on full moons.

• 10:56Wendy Zukerman?

  Okay.

• 10:56Speaker 07

  It came out a few decades ago.

• 10:58Wendy Zukerman?

  Great.

• 10:58Speaker 07

  So I got in touch.

• 11:00Wendy Zukerman?

  You reached out.

• 11:01Speaker 05

  Right around the time of the blood moon that was receiving so much popular press attention here. And every time there's something about the full moon, I kind of remember sort of nostalgically back to this study. And then the next day, I opened my email and you're like, hi, I'm Meryl.

• 11:20Wendy Zukerman?

  Whoa.

• 11:24Wendy Zukerman?

  Tell us the story of Wendy's study.

• 11:28Speaker 07

  So it all started when she was just an intern at a major trauma center in Pittsburgh. And she said that pretty quickly, she started hearing about this idea that things might get busier when there's a full moon.

• 11:40Speaker 05

  OK, so you have to picture a bunch of emergency physicians and emergency nurses sitting around, well, we don't really sit around, but you know, like in passing, or you know, you're sitting down to do your charting. And somebody says, get ready, it's a full moon tonight.

• 11:59Speaker 07

  What did they mean?

• 12:00Speaker 05

  Oh, we're going to have all these terrible accidents. Or, you know, you just can't even imagine. Here I am, like a lowly intern, and like all of these super experienced emergency department nurses and physicians are like gearing up for just like this intense night shift. And so I was like, OK, well, this must be something.

• 12:27Wendy Zukerman?

  Yep, yep, yep, yep, yep, yep, yep.

• 12:30Speaker 07

  Are you the coyote?

• 12:32Wendy Zukerman?

  Yeah, well, everything inside of me wanted to go, oh. And then I realized that's no longer factually acceptable.

• 12:40Speaker 07

  But those were during a new moon. We have to rebrand the coyote.

• 12:46Wendy Zukerman?

  Corals don't make any noise. OK, so Wendy, all her superiors believe this to be true. What happens next?

• 12:56Speaker 07

  Well, so then she decides to do like a proper study on this. So here's what they did. She worked with her advisor and they got the records from her trauma center for a year. Over 1,400 people altogether. And she looked to see like how many. People were admitted, how bad are people's injuries, whether or not they died. And then they took the day of the full moon and also the day before that and the day after it to kind of look at all those nights around the full moon. And then compare those nights to every other night of the month to see like, OK, is there any difference here?

• 13:30Wendy Zukerman?

  Was this night different to all other nights?

• 13:33Speaker 07

  Yeah. Yeah, here's what she saw.

• 13:36Speaker 06

  It was pretty funny because we're like, hmm. It looks like there's no difference.

• 13:43Wendy Zukerman?

  Oh, no difference.

• 13:45Speaker 07

  Yeah, there was no increase in how many people were admitted, how bad their traumas were, or how many of these patients died around the full moon.

• 13:54Speaker 06

  And in fact, well, maybe there are fewer traumas and less severe traumas on the actual full moon days than the other days.

• 14:07Wendy Zukerman?

  Less, less severe traumas, she said.

• 14:11Speaker 07

  Yeah, a little bit, which she thought about it and was like, oh, maybe this makes sense because on those nights.

• 14:19Speaker 06

  It's brighter. So maybe it's easier to drive on dark country roads where lots of motor vehicle accidents occur. Maybe you're not quite as likely to go stab somebody because you'd be more visible to more eyewitnesses.

• 14:39Speaker 07

  And since Wendy's study, others have come out looking at the same thing across the world. Like, a couple of studies from the Netherlands did see a tiny decrease in traumas on a full moon.

• 14:50Wendy Zukerman?

  Decrease, again, decrease.

• 14:52Speaker 07

  Yeah, yeah, it was like better. And overall, a review of these studies said that there's no increase in how busy emergency departments are during a full moon.

• 15:06Wendy Zukerman?

  All right. So Wendy, does she, does she worry when there's a full moon these days?

• 15:13Speaker 07

  No, yeah, I asked her because she actually still works in an ER. Now, when you hear people mention this idea that, oh, it's a full moon tonight, get ready, do you say anything?

• 15:25Speaker 06

  Nope.

• 15:26Speaker 07

  No?

• 15:28Speaker 06

  I never do because, you know. Like, you don't want to be that person. And you're like, actually, we studied this and we found that blabbity, blabbity, blah. Like, you just don't want to be that person.

• 15:42Wendy Zukerman?

  Do you, do you know, I feel like this will really land the point. Hashtag not all Wendy's, you know?

• 15:49Speaker 07

  Or not, well, actually Wendy's?

• 15:50Wendy Zukerman?

  Yeah. Some of us are well, actually Wendy's. Some of us are not.

• 15:57Speaker 07

  And Wendy had this really lovely theory as to like, why this idea sticks around the ER despite the lack of evidence.

• 16:04Speaker 06

  You know, like, if you have a group of people and they're united against some sort of assault. So, you know, you're going to have this night that's crazy busy. You're not going to get to eat. You're not going to get to go to the bathroom. But yeah, we can all unite on the reason.

• 16:21Speaker 07

  Yeah.

• 16:21Speaker 06

  Just like, yeah, yeah.

• 16:23Speaker 07

  It's like bonding.

• 16:24Speaker 06

  It's bonding time and we can't predict who's coming. We can't predict how busy it's going to be. But what we can predict is that we're all there for each other. And that sometimes something like talking about a full moon or the little look you give up to the sky as you're walking past one another gives you a little bit more encouragement to help you do your job well and be together with your team to take care of all the patients who come in.

• 16:53Speaker 07

  Isn't that nice?

• 16:55Wendy Zukerman?

  It is nice. It is nice. If only we could all be united by the full moon.

• 17:00Speaker 07

  Yeah.

• 17:01Wendy Zukerman?

  So where do we go to here?

• 17:03Speaker 07

  Okay, well, so, yeah, it doesn't seem like the full moon makes ER is busier. By the way, I also looked into this idea that there's more crime on a full moon. A couple of studies looked at that and did not see anything there either.

• 17:15Wendy Zukerman?

  Okay.

• 17:16Speaker 07

  But Wendy, this does not put the kibosh on the whole idea that the moon can affect our behavior. Actually, after doing all of this research, I am more of a true believer.

• 17:30Wendy Zukerman?

  Really? Merrill Hahn, never thought I'd see the day. Merrill Hahn PhD.

• 17:35Speaker 07

  I know.

• 17:36Wendy Zukerman?

  What did you find?

• 17:38Speaker 07

  Okay, so there is this one super interesting study that I want to tell you about.

• 17:42Wendy Zukerman?

  Okay.

• 17:43Speaker 07

  All right, so it was done by Professor Aracio de la Iglesias at the University of Washington in Seattle. Have you ever howled at the moon?

• 17:51Speaker 05

  Not really, not yet.

• 17:54Speaker 05

  But maybe, you know, if I keep doing research on it, I might end up doing that.

• 17:58Wendy Zukerman?

  Well, I think if he keeps doing research on it, he'll know that that's a myth, Merle.

• 18:03Speaker 07

  That's true. Oh, but so he's done fieldwork in Argentina, where he's from, with a group of indigenous people, the Toba Com, who are living in a really remote area with no electricity. And he was curious whether, living in these conditions, the moon might be affecting their sleep.

• 18:25Wendy Zukerman?

  Their sleep?

• 18:26Speaker 07

  Yeah.

• 18:27Speaker 05

  Essentially, they live very much in tune with the natural daylight and the natural light-dark cycle.

• 18:34Speaker 07

  So there was no streetlights, no?

• 18:36Speaker 05

  No, no streetlights, no lights in the houses.

• 18:40Speaker 07

  So he asks people to wear a device on their wrist, sort of like a Fitbit, but fancier, that tracks their sleep. Twenty-five people agreed to do this. And then he, like, plotted out all of this sleep data next to the, like, lunar cycle to see if there were any patterns.

• 18:58Wendy Zukerman?

  So if, on a full moon, people slept more or less?

• 19:04Speaker 07

  Yeah. And he did see that on the days leading up to a full moon, people were sleeping less.

• 19:11Speaker 05

  People were going to bed much later, up to an hour later, and sleeping by about an hour less.

• 19:17Speaker 07

  Huh. That's a pretty big effect.

• 19:19Speaker 05

  Yeah, that's a huge effect in sleep terms, right?

• 19:22Speaker 07

  On average, it was about a 45-minute difference.

• 19:26Wendy Zukerman?

  Hmm.

• 19:26Speaker 07

  And Arasio thought that it was probably the brightness of the moon that was doing this.

• 19:30Wendy Zukerman?

  Yeah, right.

• 19:31Speaker 07

  Particularly for this community.

• 19:33Speaker 05

  We don't realize how bright the moon is, particularly when you are under totally natural light conditions, right? Because suddenly, the sun sets, it gets very dark. And if the moon happens to come up just before, you know, you're about to go to bed, it's nearly impossible to go to bed, right? You see the moon there.

• 19:55Speaker 07

  It's that bright out there.

• 19:56Speaker 05

  Exactly. You know, you could even read under full moonlight.

• 20:00Speaker 07

  Oh, wow.

• 20:02Speaker 07

  So then Horacio decides to look at places that weren't rural, like cities. He starts with a group of Tobacol people who are living in a more urban area. And weirdly, he found that their sleep was still affected by the moon. So now Horacio is like, okay, let's run the experiment again where he lives in the US, in Seattle, in Washington State. He gets sleep data from about 120 people there, mostly young adults. And he still sees the same pattern. So these people living in Seattle were also sleeping less on the nights leading up to a full moon by like 20 to 40 minutes.

• 20:47Wendy Zukerman?

  And so now he's sure it's not the brightness of the moon anymore?

• 20:51Speaker 07

  Well, yeah, because this is Seattle. Like, it's cloudy most of the time in the winter there. And Horacio is still seeing this pattern, even in the winter. And then the moonlight is also competing with other forms of light in a city. Like, apparently, the moon, even when it's full, is still something like 50 times less bright than a single streetlight.

• 21:13Speaker 05

  The fact is that we see very clear lunar rhythms in people living in a place where light pollution is way above the intensity of full moon nights. And we cannot explain that by moonlight.

• 21:29Wendy Zukerman?

  So what's going on? Was it just that they were partying more on a full moon?

• 21:36Speaker 07

  Yeah, you mean like going to like full moon parties?

• 21:39Wendy Zukerman?

  I guess so. Well, you know, sitting out in the park, watching the full moon.

• 21:43Speaker 07

  I don't think so, because when you look at the data, it's not like people were like suddenly sleeping less just on the night where there was a full moon. What you actually see is this pattern where you kind of like sleep less and less gradually in the days leading up to the full moon. And then it kind of peaks. And then you start sleeping more and more and more. And then the full moon happens and you keep sleeping more and more. And it kind of goes like up and down, up and down in this like wave pattern. And Horacio saw this across all his data.

• 22:15Speaker 05

  By now, I have no doubt that there's a lunar month modulation of sleep, particularly when you see single people doing this beautiful sinusoidal.

• 22:27Speaker 05

  Oscillation in their sleep.

• 22:29Speaker 07

  Would you want to see the wave pattern?

• 22:30Wendy Zukerman?

  Yeah. Oh, yeah. Yeah, there's a very nice wave pattern there. Very intriguing.

• 22:39Speaker 07

  It's a beautiful sinusoidal pattern.

• 22:41Wendy Zukerman?

  It is a beautiful sinusoidal pattern.

• 22:45Speaker 07

  So, yeah, it really doesn't feel like you could like create that pattern of sleep, even if you tried, right? It's not like people partying a little bit more.

• 22:53Wendy Zukerman?

  Yeah.

• 22:54Speaker 07

  And if the moon affects our sleep, then that kind of opens the door to it maybe affecting us in other ways too, because we know that sleep can affect our mood and our mental health. And in fact, like, there are actually studies on bipolar disorder, specifically this thing called rapid cycling bipolar disorder. And what the researchers are seeing there is that these patients seem to like be switching between mania and depression in a timing that kind of lines up with the cycles of the moon. And those researchers also think this could be related to sleep. Like, maybe if you're losing sleep around the full moon, it might kind of trigger a manic state.

• 23:40Wendy Zukerman?

  What?

• 23:41Speaker 07

  And so now Horacio and some other scientists believe that like, yeah, it does seem like the moon is doing something strange here, that it's like somehow changing our bodies and our brains and affecting our sleep. And it's not just about how bright it is or partying more or whatever. It's like there's something else.

• 24:03Wendy Zukerman?

  What, though? How is it doing it?

• 24:06Speaker 07

  Well, exactly, right? That's what we'll look at after the break.

• 24:17Speaker 07

  Gray roots entering the chat, uninvited? Garnier's got you. Garnier Color Sensation Root Retouch covers up to 100% of grays in just 10 minutes. No ammonia, no mess, and the color lasts up to four weeks. It's as easy to apply as shampoo. Plus, it's vegan and cruelty free.

• 24:35Speaker 06

  Ten minutes. Sensational color, sensational price. With those savings, your next girls' night is basically free. Find your perfect match at walmart.com or at a store near you.

• 24:47Speaker 06

  Did you know that psoriatic arthritis may progress over time and could cause permanent joint damage if left untreated?

• 24:58Speaker 06

  Listen to what it sounds like to be a million miles away.

• 25:06Speaker 06

  Trimfyia gusalkumab, taken by injection, is a prescription medicine for adults with active psoriatic arthritis. Serious allergic reactions, increased risk of infections or lower ability to fight them, and liver problems may occur. Before treatment, get checked for infections and tuberculosis. Tell your doctor if you have an infection, flu-like symptoms, or need a vaccine. Imagine being a million miles away. Explore the possibilities. Ask your doctor about Trimfyia. Tap this ad to see new joint data and learn more about Trimfyia, including important safety information. Are you looking for support in your weight management journey?

• 25:50Speaker 06

  Zepbound terzepatide may be able to help. Zepbound is a prescription medicine used with a reduced calorie diet and increased physical activity to help adults with obesity, or some adults with overweight who also have weight-related medical problems, to lose excess body weight and keep the weight off. Zepbound is approved as a 2.5, 5, 7.5, 10, 12.5, or 15-milligram injection. Zepbound contains terzepatide and should not be used with other terzepatide-containing products or any GLP-1 receptor agonist medicines. It is not known if Zepbound is safe and effective for use in children. Don't share needles or pens or reuse needles. Don't take if allergic to it, or if you or someone in your family had medullary thyroid

• 26:33Speaker 06

  cancer, or if you've had multiple endocrine neoplasias. Tell your doctor if you get a lump or swelling in your neck. Stop Zepbound and call your doctor if you have severe stomach pain or a serious allergic reaction. Severe side effects may include inflamed pancreas or gallbladder problems. Tell your doctor if you experience vision changes before scheduled procedures with anesthesia. If you're nursing, pregnant, plan to be, or taking birth control pills. Taking Zepbound with a sulfonalurea or insulin may cause low blood sugar. Side effects include nausea, diarrhea, and vomiting, which can cause dehydration and worsen kidney problems. Talk to your doctor. Call 1-800-545-5979, or visit zepbound.lily.com.

• 27:18Speaker 01

  This episode is brought to you by Petivity. Cat parents are basically mealtime detectives. Who actually ate? Did they finish? Was that less than yesterday? The new Petivity Smart Feeder for cats turns everyday meals into meaningful health insights, helping you identify changes in your cat's habits and be more proactive about their health. Plus, you can feed them from anywhere. Take the mystery out of mealtime. Visit petivity.com, P-E-T-I-V-I-T-Y.com/catfeeder to learn more.

• 27:50Wendy Zukerman?

  Welcome back. Meryl has promised to tell us why the lunar cycles might be getting into our body and somehow affecting our sleep. I don't know. What's going on here, Meryl? This is strange.

• 28:04Speaker 07

  Well, I mean, this is where things get exciting, right? Because now we have this thing that the moon is doing to us, and we just need to figure out how. And, you know, when I talk to people on the streets about this, about how the full moon could be affecting us, they had all sorts of ideas.

• 28:21Speaker 03

  I definitely think this is an energy thing. It's because all of us are really here in a sea of energy.

• 28:27Speaker 04

  It's that energy. I feel like energy, like different types of energy, like that you... I don't know. I feel like it is.

• 28:35Speaker 03

  We're made of like 70% water and like the moon controls the tide. So it would make sense that it has an effect on us, too. Humans are 70% water, so the moon is going to automatically influence us if we are water.

• 28:49Speaker 07

  Adults are actually only like 55% water. But anyway, let's, let's look at this. Because like the general idea is that we know the moon creates tides in the oceans

• 28:59Wendy Zukerman?

  Yes.

• 29:00Speaker 07

  Uh, through like the pull of its gravity on water. So what if it's doing something similar to us?

• 29:05Wendy Zukerman?

  Right, okay. And is there any evidence for that?

• 29:08Speaker 07

  Well, first, my question actually was just like, okay, sure. It's like pulling on us a little bit, but like, how much? Like, is it realistic that it's a big enough force to do anything? So I asked an astronomer and a tidal expert. And they didn't like laugh it off completely, but they did the calculations on like how big the forces were.

• 29:29Wendy Zukerman?

  Right.

• 29:29Speaker 07

  And they were tiny, like miniscule.

• 29:32Wendy Zukerman?

  Hmm.

• 29:33Speaker 07

  One of them found that the force of the moon's gravity on our bodies is less than if you were just like walking by a tall building. Like, that building next to you would have a bigger force on our bodies than the moon because it's like a lot closer.

• 29:48Wendy Zukerman?

  Yes. Okay.

• 29:52Speaker 07

  But still, like, just because the force is small doesn't mean that it's not doing anything to anybody. Like, I wondered if we knew of any animal that can sense this, this pull from the moon and thought of the animals that like live in the tidal zone? Because those animals are really affected by the moon's gravitational pull. How big the tides are has this huge impact on their day-to-day life.

• 30:20Wendy Zukerman?

  Right. And so how are they detecting those changes? Is it just, you know, through the water or gravitational changes directly from the moon?

• 30:31Speaker 07

  Yeah.

• 30:34Speaker 07

  So to find out, I called Professor Kristin Tesmer-Reble at the University of Vienna in Austria, since she wrote a review about how animals are affected by the moon in different ways.

• 30:44Wendy Zukerman?

  Great.

• 30:44Speaker 07

  So I asked her, "Do we know of any organism that can directly sense the changes from the moon's gravity?"

• 30:52Wendy Zukerman?

  Oh, I don't know. No. Um.

• 30:58Speaker 07

  Who uses it? I mean, not, I mean, you mean not, obviously, tidal changes? Not being jostled by the tides, yeah, but like directly sensing the moon's gravity. Sensing it, uh, I, I am not aware of something like this. So, yeah, the case for gravity, I'd say, is pretty weak.

• 31:17Wendy Zukerman?

  Much like the gravitational force of the moon on us.

• 31:20Speaker 07

  Yeah, exactly.

• 31:21Wendy Zukerman?

  Okay, so it's probably not gravity. What else is there?

• 31:26Speaker 07

  Well, there's one other thing.

• 31:28Wendy Zukerman?

  Mm-hmm.

• 31:29Speaker 07

  So the Earth has this super cool magnetic field around it.

• 31:34Wendy Zukerman?

  Right.

• 31:34Speaker 07

  And as the moon revolves around the Earth, it seems to like mess with this field. And we do know that some animals can sense the Earth's magnetic field. We know organisms, like migratory birds, that use that for their long-distance flights. And, and, and it's not, and it's actually not only birds, also butterflies sense the magnetic field. And the way we think that they're doing this is through this protein called cryptochrome.

• 32:06Wendy Zukerman?

  Uh-huh. Sounds like something I should have invested in 10 years ago. What, what is it?

• 32:11Speaker 07

  Um, okay, so, yeah, cryptochrome is a protein in our bodies that can interact with the magnetic fields. And it seems to be helping the birds know which direction to fly.

• 32:23Wendy Zukerman?

  Uh-huh. And do, do humans have cryptochrome?

• 32:28Speaker 07

  We do. We do have a version of cryptochrome. It's not the exact same protein that the birds have. But we actually do have a little evidence that our cryptochrome can sense the magnetic fields, too.

• 32:41Wendy Zukerman?

  Uh-huh.

• 32:42Speaker 07

  And so maybe that's how the moon's affecting us. Because like, okay, what we would be looking for if, you know, the Earth's magnetic field is the missing link.

• 32:50Wendy Zukerman?

  Right.

• 32:51Speaker 07

  It, maybe it should have a similar kind of wave pattern, like that sinusoidal curve that we saw in Horacio's leap data. And then I stumbled on this graph where I was like, whoa, all right, let me, let me show this to you.

• 33:06Wendy Zukerman?

  Show, show me the whoa graph. Is it the sinusoidal again? Because I don't know if I can handle that, Meryl. I don't know if I can handle it.

• 33:13Speaker 07

  So let's go to scroll down in the script.

• 33:16Wendy Zukerman?

  Whoa!

• 33:20Speaker 07

  So sinusoidal again.

• 33:22Wendy Zukerman?

  She's shy.

• 33:28Speaker 07

  Yeah.

• 33:28Wendy Zukerman?

  If you didn't think you were listening to a nerdy podcast, you don't know. That is, okay, so what is, what is, is this magnetic field?

• 33:39Speaker 07

  Yeah, this is the change in magnetic fields over a lunar cycle. So the line in the middle is the full moon. The magnetic field is apparently lower in the days leading up to a full moon, just like Erasio saw, and then it gets like higher after the full moon. But I don't know if I've gone off the deep end. Like this paper is, you know, it's from like the 1960s, like.

• 34:01Wendy Zukerman?

  Yeah, it's hand drawn, it's hand drawn, that's for sure.

• 34:07Wendy Zukerman?

  Like someone used a ruler to make those lines. Okay, so what this shows us is that the moon affects the magnetic field in this sinusoidal pattern that is similar to the way that the moon seems to affect our sleep. Step one, but then step two, has anyone figured out if the cryptochrome in us is actually detecting those changes to the magnetic field? And that that is then affecting our sleep?

• 34:45Speaker 07

  No, like, nobody's actually like connected all the dots here to find out, okay, can we really sense the magnetic fields at all? And can that mess with our sleep? When Kristen was explaining this to me, there was lots of like hand waving going on and like emphasis that it's like all kind of just theoretical. So it's really unclear still.

• 35:10Wendy Zukerman?

  But this is a lot of wild speculation, I have to emphasize.

• 35:15Speaker 07

  Yeah, she said that this question of whether the moon is having like a subconscious effect on us is at the frontiers of our knowledge. It's like a black hole. But that doesn't mean that it's impossible or like a silly idea. Just because it is a subconscious phenomenon, it doesn't mean that it doesn't exist. Right? I think people tend to say, oh, I cannot.

• 35:39Speaker 06

  Feel it and therefore it doesn't exist. But we usually don't feel our liver, um, at least hopefully not, but it's very existing, right?

• 35:49Speaker 07

  Yeah. It's doing all sorts of stuff to us.

• 35:52Speaker 06

  Exactly, exactly. So I mean, the fact that we are not consciously aware of something is is true for a lot of our physiology.

• 36:00Speaker 07

  Do you think that the moon for sure is influencing people?

• 36:05Speaker 06

  I think yes. The reason why I think yes is that for me as a biologist, for me as a biologist, humans are just another type of animal.

• 36:15Speaker 07

  Were made of the same stuff as the worms.

• 36:17Speaker 06

  Exactly, worm at at the end, exactly, like this, with some few specifications that are a bit different.

• 36:25Speaker 06

  From the larger perspective, it's marginal, so.

• 36:32Wendy Zukerman?

  Okay, so here's where we are at. The cycles of the moon do seem to affect our sleep somehow. We're not sure how. Last question, can it affect blood coming out of our vaginas?

• 36:51Speaker 07

  You mean our menstrual cycles?

• 36:52Wendy Zukerman?

  Yes.

• 36:53Speaker 07

  Yeah, let's look at that. It comes up all the time. I've heard from a lot of people who think there's something there. So, yeah, I I called up a scientist who did a pretty wild study on this.

• 37:06Wendy Zukerman?

  Do you know, describing describing a period based study as a wild study is immediately making me think of just a scientist throwing around dirty tampons for some reason.

• 37:21Wendy Zukerman?

  I don't know why.

• 37:24Speaker 07

  I mean, it's not, it doesn't go that carnal, but it's, you know.

• 37:28Wendy Zukerman?

  Like how?

• 37:28Speaker 07

  As well in its own way.

• 37:32Speaker 07

  All right, let me tell you about it. Okay, okay. So the idea first came to her when she had this commute where she was walking a lot at night.

• 37:41Speaker 05

  I was walking from the train station to my home, family home.

• 37:46Speaker 07

  And what did it look like on a night when there was a moon?

• 37:49Speaker 05

  Oh, fantastic, because you could see everything. You don't need lights in the street. So I always loved the moon to be out.

• 37:57Speaker 07

  This is Charlotte Helfrich Forster, senior professor at the University of Wurzburg in Germany. And she noticed something about her period around this time.

• 38:06Speaker 05

  My first day of menses was always around the full moon. And then I was really astonished, oh, that's interesting.

• 38:14Wendy Zukerman?

  Do you know, Meryl, I'm the exact opposite, that I will ovulate around a full moon and get my period, I guess, in a new moon. But I just assumed it was because I'm a pretty regular cycle. And that's just what a month is, you know, around 28 days or whatever.

• 38:34Speaker 07

  Sure, but like, if you think about it, even that's pretty weird, right? Like, that for a lot of us, our periods just happen to be 29 days long, which is the same length as the lunar cycle?

• 38:48Wendy Zukerman?

  I guess so, right. Yeah, why are our cycles the same as the cycles of the moon? Okay, yeah.

• 38:58Speaker 07

  I mean, yeah, it could just be a coincidence. But maybe something else is going on here. And so like for Charlotte, she started wondering, how long have I been getting my periods at the full moon?

• 39:11Wendy Zukerman?

  Right.

• 39:11Speaker 07

  And luckily enough, she had actually been keeping track of when she was getting her period for basically her entire life.

• 39:20Wendy Zukerman?

  Oh, wow.

• 39:21Speaker 07

  Like she started when she first started getting her period.

• 39:23Speaker 05

  My mother told me to make always a cross in my calendar at the first day.

• 39:28Speaker 03

  Of my menses. So I did it without thinking.

• 39:31Speaker 07

  And kept all these little calendars at her home in a cabinet. And so now she she went back to check like, is this, has this always been a thing for me?

• 39:40Wendy Zukerman?

  Amazing.

• 39:41Speaker 07

  And just by eye, she could tell that like, oh, yeah, for like many years of my life, I've either been synced with a full moon or sometimes it was the new moon. And so she starts wondering, all right, how how many people is this like true for? So she asks her mom and her sister if they kept their calendars, and they did. And she looked at their data and saw similar stuff.

• 40:04Speaker 03

  But of course, as a scientist, you know that three examples are not enough. And then I started to ask colleagues, friends, whether they by chance had kept any recordings of her menses.

• 40:16Speaker 07

  And so it took her about 10 years to collect this data from 22 women who had kept track of their cycles for an average of 15 years of their life.

• 40:26Wendy Zukerman?

  Wow, OK.

• 40:26Speaker 07

  And so now we can find out, do people on average get their periods more often around the time of a full moon?

• 40:33Wendy Zukerman?

  Great. So what did she find?

• 40:35Speaker 07

  She saw that, yeah, there was something there. So in this group of 22 women, they were more likely to start their periods either around the time of a full moon, like especially the days leading up to a full moon or the new moon.

• 40:51Wendy Zukerman?

  Oh, how curious.

• 40:54Speaker 07

  But like, I'm one of these people who does not think this is true for me. So I asked, how strong of an effect was it? Since I was curious, I looked at my data for the past few months, and it definitely was not syncing to the full moon.

• 41:08Speaker 03

  That is very important. The effect is really very small. And to be honest, when you look at your entire cycle, it's only a small part during a cycle that is synchronous to the moon.

• 41:21Speaker 07

  So, yeah, I mean, obviously, it's not like everyone's getting their periods on the full moon.

• 41:25Wendy Zukerman?

  Yeah, right.

• 41:26Speaker 07

  It more, it's more like it up to your chances a little bit that you'd get your period on either a full moon or a new moon.

• 41:33Wendy Zukerman?

  OK.

• 41:34Speaker 07

  But there's something else that I need to tell you about her study. So after it came out in 2021, all these other women start sending to her a lot of their calendars. They're like when they got their period. So then she got data from more than 100 other people and she tried crunching the numbers again. And here's what happened.

• 41:56Speaker 03

  I was absolutely disappointed when I pulled all the data, the new data that I had. I didn't see any synchronization to the moon anymore. So it was very different from my first study with the 22 women.

• 42:11Wendy Zukerman?

  Ah, that classic thing where you study something in a few people, get very exciting results. And then you study it in more and more people and realize it's not generalizable. We've seen this countless times before. Charlotte and I are the anecdote in the room that gets the headlines. Okay.

• 42:32Speaker 07

  I mean, Charlotte still thinks there could be something here. Like she's been looking into whether light pollution is a factor. But she also pointed me to some other data like, okay, so there is an analysis that came out recently from a period tracking app. And it looked at seven and a half million cycles and they didn't see any sinking to the moon whatsoever.

• 42:56Wendy Zukerman?

  This has actually made me feel more like a witch, you know? Because obviously we couldn't.

• 43:00Speaker 07

  Because it's so rare?

• 43:01Wendy Zukerman?

  Yeah, we couldn't all be witches, you know?

• 43:04Speaker 07

  Well, I'm glad you feel special now. That's what I'm here for.

• 43:09Wendy Zukerman?

  But I guess we're all a bit witchy because the moon is affecting all of our sleep in this mysterious way.

• 43:19Speaker 07

  Don't patronize me just because I have sleep still. I don't feel like a witch.

• 43:29Speaker 07

  It's okay.

• 43:34Speaker 07

  Do you think that the moon is affecting you?

• 43:36Wendy Zukerman?

  Hmm, I, I really love, I love the moon. I love a big full moon. I like looking at it. I like thinking how small I am in this big universe. Reminds me of that. I love when you see it rising and it's just huge.

• 43:58Speaker 07

  Hmm.

• 43:59Wendy Zukerman?

  I love it for all those reasons. I don't, I don't know if it's having some deeper subconscious effect on my body. What about you, Meryl? You've been, you've been researching this for a while. Has it changed your view of the moon?

• 44:14Speaker 07

  Yeah, I think it, I don't know. I feel like now I am less skeptical. Like when I was in the park and everybody was telling me about how they felt like the moon was just changing the energy and like they could feel it and that they knew there was like something there. I was just like rolling my eyes and like, sure, it's like changing the energy. But now I'm like, oh, actually, maybe it is. It's the magnetic fields, which is like a kind of energy. It's just so mysterious. There is an effect, at least on our sleep, that we don't understand yet. And I feel like I'm more humble now about like what's possible with our bodies and the moon.

• 44:56Wendy Zukerman?

  Do you want to yip with me?

• 44:58Speaker 07

  Yep, yip, yip, yip, yip, yip, yip, yip, yip, yip. Thanks, Meryl. Thanks, Wendy.

• 45:03Wendy Zukerman?

  All right, Meryl, how many citations in this week's episode?

• 45:05Speaker 07

  This week, we have 52 citations. And if you go to our show notes, you can find links to the transcripts, where you can see all of them and read more about the moon.

• 45:15Wendy Zukerman?

  Excellent. If you want to tell us what you thought of this episode, we'd love to hear from you. We are at science underscore V S on Instagram. I'm at TikTok at Wendy Zook. Thanks, Meryl. Have a happy full moon.

• 45:28Speaker 07

  Oh, yeah. Be careful.

• 45:38Speaker 07

  This episode was produced by me, Meryl Horn, with help from Wendy Zukerman, Rose Rimler, Michelle Dang, and Aketi Foster Keys. We're edited by Blythe Sorrell. Mix and sound design by Boomi Hidaka. Fact checking by Marlo Starling. Music written by Boomi Hidaka, Bobby Lord, Emma Munger, So Wiley, and Peter Leonard. Thanks to all the researchers we spoke to for this episode, including Dr. Ron Flick, Dr. Michael Smolensky, Michael Bevington, Dr. Laurel Sims, Professor Laura Prugh, and Dr. Martin Neiston. Special thanks to Kevin Walsh and all the folks who chatted with me about the full moon. Science Versus is a Spotify Studios original. Listen for free on Spotify or wherever you get your podcasts. And if you do listen on Spotify, follow us and tap the bell

• 46:23Speaker 07

  for episode notifications. We'll fact you soon.

• 46:37Speaker 06

  From the creators of Zootopia and Frozen comes Disney's Hext. Welcome to Hext and enter the world of witches, where it was foretold that an ordinary girl would become an extraordinary witch and save the world of magic. Disney's Hext arrives in theaters this Thanksgiving.

• 46:57Speaker 01

  This episode is brought to you by State Farm. Football has a play for just about everything. You can go deep, keep it on the ground, or draw up something nobody sees coming. And whether you want to run a flea flicker or the tush push, you need a plan to fit your unique situation. That's why State Farm takes the time to get to know you, so they can help personalize coverage for your life and budget. Now that's a solid game plan. Like a good neighbor, State Farm is there.