Kelly Burch is a freelance journalist who has covered health topics for more than 10 years. Her writing has appeared in The Washington Post, The Chicago Tribune, and more.

Sanja Jelic, MD is board-certified in pulmonary disease, sleep medicine, critical care medicine, and internal medicine. She is an assistant professor and attending physician at Columbia University College of Physicians and Surgeons in New York, NY .

You toss and turn, unable to fall asleep and wondering why. Then you peek behind your curtain and see a full moon shining bright. It’s a common experience that might leave you wondering if a full moon actually does affect sleep.

Although it seems like an old wives’ tale, research shows that the moon phases can impact a person’s sleep.

This article provides information about the lunar cycle and how knowing the date of the next full moon could help you get more sleep. 

How much of the moon we see each night is dictated by where the earth, moon, and sun are in relation to one another as they rotate. A full moon occurs every 29.5 days when the sunlight from the earth reflects off the side of the moon that we can see from earth. This creates the bright orb we associate with the full moon.

The opposite of a full moon is a new moon. During this stage, the sunlight reflects off the side of the moon that we cannot see from earth. From our vantage point, it looks like there is no moon on those nights.  

Anecdotally, nearly everyone has experienced disrupted sleep during a full moon or knows someone who has. Surprisingly, science backs this phenomenon up, showing that a full moon does cause people to sleep less.

Here’s what researchers have found:

Scientists aren’t exactly sure why the moon might impact sleep. The light from the full moon may affect the body’s internal clock and its production of melatonin, a hormone that promotes sleep. Humans may have evolved socially to take advantage of the natural light produced by a full moon before there was access to light with the flick of a switch. 

However, research shows that people sleep more poorly during a full moon, even when they’re in a dark room, so the impact of a full moon goes beyond just light exposure. A full moon can affect the earth’s magnetic field or gravitational pull, but the connections between these factors and sleep have not been explored.

While research on the lunar cycle and sleep has improved, there’s a need to better understand how the moon phases affect other areas of health. A small study reported that menstrual cycles might align with the moon, mainly when exposure to artificial light was limited.

Some research has indicated that episodes of mental health illness and of violence may increase during the full moon. Still, researchers haven’t been able to document the often-touted theory that more women give birth on nights with a full moon.

No matter the lunar cycle, focusing on good sleep hygiene can help you get a better night’s sleep. Incorporate these tips for a healthier bedtime routine:

Don’t force yourself to stay in bed if you’re tossing and turning. Instead, relax quietly in another area of your home until you feel sleepy. 

The idea that a full moon can disrupt sleep isn’t just an old wives’ tale. Researchers have found that people take longer to fall asleep and sleep less when a full moon is out, even in a dark room. Despite the lunar cycle, practicing good sleep hygiene, like having a consistent bedtime routine, can help you get better sleep. 

Whether you have black-out curtains or are sleeping beneath the stars, a full moon can affect your ability to fall asleep. Luckily, the full moon only comes once every 29.5 days, so if you didn’t sleep well last night, you might have better luck in the coming days.  

A full moon can affect tides, the earth’s magnetic field, sleep, and possibly other areas of human health. Tides are higher during full moons, and people get less sleep on nights with full moons. Scientists are still working to understand the impact of a full moon fully. 

A full moon occurs every 29.5 days. It lasts just one night, but the moon can be very bright and prominent in the days leading up to and following the full moon.

Tossing and turning night over night can have a big impact on your quality of life. Our free guide can help you get the rest you need. Sign up for our newsletter and get it free.

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Casiraghi L, Spiousas I, Dunster GP, et al. Moonstruck sleep: Synchronization of human sleep with the moon cycle under field conditions. Sci Adv. 2021;7(5):eabe0465. DOI: 10.1126/sciadv.abe0465

Shoes, Sarah. Do moon phases affect your sleep? Sleep Foundation.

Cajochen C, Altanay-Ekici S, Münch M, Frey S, Knoblauch V, Wirz-Justice A. Evidence that the lunar cycle influences human sleep. Curr Biol. 2013;23(15):1485-1488. doi: 10.1016/j.cub.2013.06.029

Helfrich-Förster C, Monecke S, Spiousas I, Hovestadt T, Mitesser O, Wehr TA. Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the moon. Sci Adv. 2021;7(5):eabe1358. DOI: 10.1126/sciadv.abe1358

BBC. The mood-altering powers of the moon.

National Sleep Foundation. Healthy sleep tips.

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