Many people wonder whether the full moon affects our sleep and when the moon is full – especially when they realise that their sleep quality suffers on full moon nights. Is it imagination or scientific fact? A research group from Switzerland now claims: Yes, the poorer sleeping behaviour is also linked to the full moon. In a study, the sleep researchers have scientifically proven a direct link between moon phases and sleep behaviour.
Full moon nights and sleep quality
Until now, it was mainly recognised and proven that the moon has a direct influence on the earth and humans in many ways. The tides with ebb and flow as a result of gravity between the earth and the moon are the best example of this. However, the fact that the full moon phase also influences human sleep has always been suspected, but has not yet been clearly scientifically proven.
This is where the Swiss sleep researchers came in with their study. The sleep quality of study participants was tested in a sleep laboratory without a window. They were able to prove a clear connection between the full moon and changes in sleep quality. They found that the deep sleep phases were shortened on nights with a full moon and that it took longer to fall asleep, even though there was no bright moonlight or similar to indicate the full moon. It is therefore no coincidence that many people complain of poorer, restless or shorter sleep on full moon nights.
Why we can’t sleep under a full moon.
The researchers used a brain wave measurement to document behaviour in the various sleep phases and also recorded the levels of the sleep hormone melatonin. On average, the participants fell asleep five minutes later and their sleep time was 20 minutes shorter overall. The poorer sleep can be attributed to a lower melatonin level at full moon. In addition, the brain wave measurement showed that the activity of the brain areas shortened the phases of deep sleep by 30 % during a full moon.
The test subjects confirmed these study results. They stated that they always slept particularly badly when the moon was full. The researchers concluded that even if you cannot see the moon and do not know what phase it is in, the lunar cycle has an influence on people’s sleep. The result is all the more astonishing as the study participants did not know what the subject and aim of the sleep studies were.
The influence of the full moon on our sleep
The question ‘When is the full moon?’ is therefore not only of astronomical interest to many, but also relevant from a health perspective. This is because the brightness of the full moon, even through windows, can inhibit melatonin synthesis and thus have a direct influence on our sleep-wake rhythm. Even if we are less directly dependent on moonlight thanks to modern lighting, moon phases appear to have a subtle effect on our internal clock.
When is the moon full?
If you want to know when the moon is full again, it’s worth taking a look at the lunar calendar. The exact time varies every month, as the lunar cycle lasts around 29.5 days. Knowing the phases of the moon can help you to better understand the connection between your personal sleeping behaviour and the full moon.
To help you prepare for the next full moon nights, we have listed the dates here:
Full moon 2025
- Friday, 5 December 2025
- Monday, 13 January 2025
- Wednesday, 12 February 2025
- Friday, 14 March 2025
- Sunday, 13 April 2025
- Monday, 12 May 2025
- Wednesday, 11 June 2025
- Thursday, 10 July 2025
- Saturday, 9 August 2025
- Sunday, 7 September 2025
- Tuesday, 7 October 2025
- Wednesday 5 November 2025
- Friday, 5 December 2025
