Your Sleep Quality Suffers Around the Full Moon

By Bill Andrews | July 25, 2013 11:06 am

full moon

The moon may be a harsh mistress, but she also might be to blame for your poor night’s sleep. A study in Current Biology shows for the first time that the moon’s shape can impact people’s sleep. Specifically, a full moon negatively affects sleep duration, deep sleep, how long it takes to fall asleep, and levels of melatonin (a sleep-related hormone).

With a study like this, it’s important to make sure that nothing unduly influences the results, and the Swiss team responsible ensured this in two ways. First, they made sure the subjects represented a wide range of people (they had 17 healthy young volunteers and 16 healthy older volunteers, with men and women in every group) and the laboratory conditions were carefully monitored and controlled for.

Second, they didn’t bring in the whole “lunar” aspect of this sleep study until much later. As the authors write in the paper, “We just thought of it after a drink in a local bar one evening at full moon, years after the study was completed.” (If it hadn’t been for that full moon inspiration, we might still not have any evidence linking lunar phase with human sleep activity!) All the recordkeeping allowed them to go back to the original data, collected from 2000-2003, and see if any of the sleep characteristics they measured had anything to do with the moon’s phase.

Full moon woes

It was a good thing they did. They found that during a full moon, it took participants 5 minutes longer to fall asleep, and overall sleep time fell by 20 minutes. This despite the fact that volunteers in the sleep study had no actual view of the moon.

In addition, sleep was less restful around the full moon. The kind of sleep activity dubbed “non-rapid-eye-movement,” which indicates deep sleep, fell by 30 percent around the full moon, and melatonin levels fell by about half. The participants reported poorer sleep than average during these times.

So while stories of increased crime sprees during full moons — or werewolves changing shape — are nothing but urban legends, we now have a definite link between the full moon and human behavior. Even with all our modern ways to artificially illuminate the night sky, its natural activity still affects us. Scientists have long known about our circadian, or daily, bodily rhythms, but this study helps shed light on the lesser-understood “circalunar” rhythms of our bodies. These phenomena are known to exist, but we know very little about them, in part because a month-long pattern is harder to observe and study than a daily one.

So next time you get a hint of the full moon fever, you know what that means: go to bed early.

CATEGORIZED UNDER: Health & Medicine, select
MORE ABOUT: moon, sleep
  • Roger

    It’s good to know that it is not just me. Some nights I just pop awake in the middle of the night unable to go back to sleep, and I often see the full moon in the sky when that happens.

    • dontmindme777

      I’m sorry, you’re actually a werewolf.

      • Warren Zevon

        Ahhwooooo… Werewolves of London


    Perhaps in many legend and myth around the world tell a story about how mesmerising the moon is and how they related in our live. In the religion, in medicine, in every aspect of our live.

    So, look out to the sky and watch for a sweet star! It might tell you something!

  • Karin dilou

    Being an extremely “earthbound” personality, I am always looking for explanations WHY when hearing some “unnatural” – often superstitious or “old wives tales” – but have heard from numerous people that they have sleep issues around full moon since that is the case with myself.. I am “moon crazy” and also get sexually aroused at fool moon. Cannot sleep – toss around in the bed and wake up bathed in sweat. Tend to forget it every month – but it has turned out always in connection with full moon. So WHAT IS it? Maybe it is the magnetic influences on line with the moon’s ability to move the tide water maybe our fluids in the body get influenced that way? My horses/mares have always given birth at full moon – so maybe the moon’s influence is breaking the water? Always easy and uncomplicated births. Would like to hear other people’s experience – it cannot ALL be a “co-incidence”.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


Briefing you on the must-know news and trending topics in science and technology today.

See More

Collapse bottom bar