Last updated: October 2026
Does the full moon cause insomnia? The research is mixed. A Swiss lab study found people slept about 20 minutes less and took 5 minutes longer to fall asleep around the full moon, but larger studies of thousands of nights found little or no effect. If there is an effect, it’s small and lasts a few nights.
Planning a calmer wind-down for full moon week? Our Magnesium Glycinate Sleep Complex is a berry drink you mix in the evening, with 148mg of magnesium per serving plus glycine and L-theanine. Magnesium contributes to a reduction of tiredness and fatigue.
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Does the full moon affect sleep? What the studies found
| Study | Who | What it found |
|---|---|---|
| Cajochen, Current Biology, 2013 | 33 volunteers in a windowless sleep lab | Around the full moon: about 20 minutes less sleep, 5 minutes longer to fall asleep, 30% less deep sleep activity |
| Casiraghi, Science Advances, 2021 | 98 people in Argentina, 463 Seattle students | Later, shorter sleep on the nights before the full moon |
| Cordi, Current Biology, 2014 | 1,265 volunteers, 2,097 nights | No meaningful link with moon phase |
| Haba-Rubio, Sleep Medicine, 2015 | 2,125 adults tested at home | No significant effect on sleep length or quality |
The lab study. The Basel team re-analysed old sleep data; nobody knew moon phase would be checked, and volunteers couldn’t see the sky. Around the full moon they also rated their sleep worse and had lower melatonin, the hormone that rises before sleep.
The field study. People wore wrist trackers for weeks. In the Argentine groups, sleep was latest and shortest 3 to 5 days before the full moon, with average swings of 46 to 58 minutes across the cycle. The Seattle students showed the same pattern.
The bigger re-analyses. In far larger sets of sleep data, the effect mostly disappeared. The Cordi team also found unpublished results showing no effect, suggesting positive findings were more likely to get published. The Basel group replied that bigger samples don’t automatically mean better data.
So a full moon may nudge sleep by minutes, not hours, and many people notice nothing.
Why you might sleep worse around a full moon
- Evening light. In the nights before a full moon, the moon is up and bright in the hours after dusk. The 2021 researchers think this early-evening light pushed bedtimes later, as screens do now. Light is one of the main signals for your circadian rhythm.
- Light through the curtains. A bright moon can light up a room with thin curtains, which matters more for a light sleeper.
- Expectation and attention. If you expect a bad night, you’re more likely to notice waking at 3am and to remember it. Good nights under a full moon go unremembered, and worrying about sleep can itself keep you awake.
Spiritual meanings are outside what science can test, but a few rough nights around a full moon are common and usually pass.
Next full moon dates in the UK
Times are for London, from the Royal Observatory Greenwich calendar (checked October 2026).
| Date | UK time | Name or note |
|---|---|---|
| Tuesday 24 November 2026 | 2.53pm | Beaver Moon |
| Thursday 24 December 2026 | 1.28am | Cold Moon |
| Friday 22 January 2027 | 12.17am | Supermoon (night of 21 January) |
| Saturday 20 February 2027 | 11.23pm | Penumbral lunar eclipse |
If the 2021 findings apply to you, the nights to plan for are the 3 to 5 before each date. December’s full moon falls in the early hours of Christmas Eve, so see our tips on how to sleep on Christmas Eve too.
What helps on full moon nights
- Make the room dark. Blackout blinds or lined curtains keep moonlight and streetlight out. If that isn’t possible, a sleep mask is a cheap fix.
- Keep your routine steady. Same wake-up time, an hour to wind down, screens off. Our bedtime routine for adults and sleep hygiene guide set it out.
- Don’t watch the clock. Turn it away from the bed. Checking the time adds pressure. If you can’t sleep, get up and do something calm in dim light until you feel sleepy.
- Try slow breathing. 4-7-8 breathing gives a busy mind a job. If you’d rather follow a light, see our guide to the Dodow sleep aid.
- Skip the lie-in. After a poor night, get up at your usual time.
More ideas: how to fall asleep fast. Waking from strange dreams? See vivid dreams.
Which Evopure product fits your wind-down?
| Evopure product | Format | When | Good to know |
|---|---|---|---|
| Magnesium Glycinate Sleep Complex | Berry drink powder, 148mg magnesium | In the evening | Magnesium contributes to a reduction of tiredness and fatigue |
| Sleep CBD Oil | Broad spectrum CBD drops with passion flower | About an hour before bed | 10mg is about 4 drops of the 500mg or 2 drops of the 1000mg |
| Reishi Cacao | Reishi hot chocolate | Earlier in the evening | Contains a little natural caffeine |
The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.
- Sleep CBD Oil is broad spectrum and THC free, with every batch third-party tested at ISO 17025 labs. Reports are on request from our lab testing page.
- All three are vegan and made in the UK. Our CBD products are on the FSA public list, linked to validated applications.
- Tracked Royal Mail delivery across the UK (delivery details). Unopened, unused items can be returned within 14 days (returns policy).
They’re food supplements, not medicines. For more on each, see magnesium for sleep, does CBD help you sleep? and our round-up of natural sleep aids in the UK.
When to see a GP
The NHS says to see a GP if changing your sleep habits hasn’t helped, you’ve had trouble sleeping for months, or it’s making daily life hard to cope with. If poor sleep comes every night, read why can’t I sleep? and our guide to insomnia.
FAQs
Can a full moon cause insomnia?
Not as a sleep disorder. One lab study linked it to about 20 minutes less sleep, but large studies found little or no effect. Insomnia lasting weeks has other causes.
Why can’t I sleep the night before a full moon?
The 2021 field study found sleep was latest and shortest 3 to 5 nights before the full moon, when it is bright in the evening. Expecting a bad night can also make one more likely.
When is the next full moon in the UK?
The next full moon is on Tuesday 24 November 2026 at 2.53pm, then Thursday 24 December 2026 at 1.28am, according to the Royal Observatory Greenwich.
Does the full moon affect mood?
There’s plenty of folklore, but researchers say there is no consistent link between moon phases and human behaviour. If your mood is low most days, talk to your GP.
Can I take magnesium or CBD on full moon nights?
Yes, as part of a normal evening routine. They’re food supplements, not medicines. Ask your GP or pharmacist first if you take medication. Adults (18+) only.
We don’t recommend our products during pregnancy or breastfeeding. All Evopure products are for adults (18+) only.
Sources
- Cajochen C et al. Evidence that the lunar cycle influences human sleep. Current Biology, 2013.
- Casiraghi L et al. Moonstruck sleep: synchronization of human sleep with the moon cycle under field conditions. Science Advances, 2021.
- Cordi M et al. Lunar cycle effects on sleep and the file drawer problem. Current Biology, 2014.
- Haba-Rubio J et al. Bad sleep? Don’t blame the moon! A population-based study. Sleep Medicine, 2015.
- Royal Museums Greenwich. When is the next full Moon? Full Moon calendar 2026, checked October 2026.
- NHS. Insomnia.
