No difference

Why "the full moon gives me a headache" is told so often

Plenty of people notice a heavy head or a migraine around the full moon, and the folk explanations come ready-made: the moon's pull tugs on the water in your body, the pressure shifts, the nerves misfire. The pain is real. The only question is whether the trigger is really the moon.

But headaches have no seismograph and no tide gauge. There is no public dataset logging "how many people had a headache tonight." So we used a proxy for the pain: how many people looked it up — the daily Wikipedia pageviews for Headache, Migraine, Cluster headache, and Tension headache. If some nights brought more pain, more people should reach for those articles.

We're honest about the proxy's limits

Pageviews are not attack counts. Many people in pain never look anything up, and traffic can move with news or seasonal interest. So this topic does not claim to measure the true incidence of headaches. It measures whether the traces of people bothered enough to search rise and fall with the lunar phase.

Still, if "the full moon brings headaches" were a strong, real pattern, a faint moon-shaped bump should bleed into the proxy. We went looking for that faint trace across roughly ten years of daily views.

How the verdict is computed

• Data is daily pageviews from the Wikimedia Pageviews API (official, bots excluded), July 2015 to the end of last year
• For each article we use the average of the "same weekday × same month" as the expected value, and compare actual ÷ expected as an index (normal = 100). Weekend and seasonal skews cancel out this way
• We mark "full moon days" (instant ±24h) and "new moon days" using the lunar phase at local noon, then compare each group's mean index against normal

See the methodology for the full criteria.

Why headaches can seem to cluster around full and new moons

In this page's data, signs of headache don't rise on full- or new-moon days. Still, many people feel that headaches come with the moon, and there are several explanations that don't need the moon to do anything directly.

1. Sleep may get a little shorter

Whether the moon affects sleep is genuinely unsettled.

• In 2013 a Swiss team reported that even people sleeping in a windowless lab took longer to fall asleep and had less deep sleep around the full moon (Cajochen et al., Current Biology)
• In 2014 a larger set of existing sleep recordings did not reproduce the effect, and the authors pointed to the "file drawer problem": striking results get published, null ones don't (Cordi et al., Current Biology)
• In 2021 a study using wrist-worn sensors found that, from Indigenous communities in Argentina to college students in Seattle, people went to bed later and slept less on the nights before a full moon (Casiraghi et al., Science Advances)

Short sleep is a well-known migraine trigger. Even if the moon trims sleep a little, that is an indirect path — moon → less sleep → headache — and protecting your sleep on bright nights cuts it off.

2. The menstrual cycle is about as long as the lunar month

Migraine tied to menstruation is well recognized, and the menstrual cycle runs close to the length of the lunar month (about 29.5 days). A headache that arrives at the same point every cycle can look, on a calendar, like a headache that arrives with the moon.

A 2021 study of long-term records found that women whose cycles were longer than 27 days were at times in sync with the moon's light or gravitational cycles — but with age and exposure to artificial light at night, cycles shortened and the sync faded (Helfrich-Förster et al., Science Advances).

3. Weather: pressure, temperature, humidity

The best-known trigger is the weather. As our full moon and air pressure page shows, full-moon days differ by under 0.5 hPa — still lost in day-to-day weather swings.

A study of 3,491 migraine visits to a Turkish emergency department over one year found no link with the lunar phase, but more visits on hot days and on days with low humidity (Yilmaz et al., 2015, American Journal of Emergency Medicine).

4. Full-moon headaches are the ones we remember

A headache on a full-moon night sticks: "of course." The quiet full-moon nights, and the headaches on ordinary days, fade. That is why this page counts daily records rather than memories.

One study did find more migraines before the new moon

In 2025 a U.S. team analyzed twice-daily headache diaries kept for about six weeks by 98 adults with migraine. Headache risk peaked one to two days before the new moon, with about 1.34× the odds of the days before the full moon, and neither sleep nor menstrual timing explained it (Yoo et al., Headache).

That study followed each person for about six weeks — roughly one and a half lunar cycles — and was a secondary analysis of data collected for another purpose. The authors themselves say more studies are needed to confirm it.

In our pageview data, Migraine lookups just before the new moon (the "Waning crescent" row above) sit at normal. Pageviews are not pain, though, so this doesn't refute the study. Taken together, neither source yet supports saying the moon brings on headaches.

How to check your own headaches against the moon

The surest evidence is your own record. Keep a headache diary: the days you had a headache, how bad it was, what you took, how you slept, and your cycle if relevant. As long as you note the date, the moon's age can be looked up later (our home page shows it every day).

After two or three months — two or three lunar cycles — you can see for yourself whether your headaches lean toward full or new moons. The same diary also helps your doctor.

When to see a doctor

This page can't give medical advice. A sudden, severe headache, the worst headache you've ever had, or a headache with numbness, trouble speaking, or a high fever needs prompt medical care whatever the moon is doing — call your local emergency number if in doubt.

If headaches come several times a month, or you're taking painkillers on many days, a doctor or headache clinic can help.

In short

Ten years of lookups don't yet show a rise in headaches on full- or new-moon days. The pain isn't imaginary, though, and there are clues — sleep, the menstrual cycle, the study of migraines before the new moon. What you can do today is watch that night's sleep and the weather. As for the moon and headaches, we'll keep recording every day, hoping to find the link one day.

Sources

• Wikimedia Pageviews API (CC0)
• Cajochen C, et al. Evidence that the lunar cycle influences human sleep. Current Biology 2013;23(15):1485-8. doi:10.1016/j.cub.2013.06.029
• Cordi M, et al. Lunar cycle effects on sleep and the file drawer problem. Current Biology 2014;24(12):R549-50. doi:10.1016/j.cub.2014.05.017
• Casiraghi L, et al. Moonstruck sleep: Synchronization of human sleep with the moon cycle under field conditions. Science Advances 2021;7(5):eabe0465. doi:10.1126/sciadv.abe0465
• Helfrich-Förster C, et al. Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon. Science Advances 2021;7(5):eabe1358. doi:10.1126/sciadv.abe1358
• Yilmaz M, et al. Meteorologic parameters and migraine headache: ED study. American Journal of Emergency Medicine 2015;33(3):409-13. doi:10.1016/j.ajem.2014.12.056
• Yoo A, et al. Waning light, waxing pain: The lunar cycle's association with migraine headache occurrence. Headache 2026;66(3):584-594 (online 2025). doi:10.1111/head.15035
• Lunar age and the instant of each phase are computed in-house from the algorithms in Jean Meeus, Astronomical Algorithms (UTC basis)