In brief
A hormone made by the pineal gland in the brain. Its levels rise in the dark, and it helps manage your body clock and get you ready for sleep.
- Research suggests melatonin supplements may help with jet lag, but there is not enough strong evidence for long-term insomnia, according to the NIH.
- Side effects of too much melatonin include daytime sleepiness, headaches, nausea and dizziness. Do not drive after taking it.
- In US testing, many melatonin products did not contain what their labels said.
How it works
Your melatonin levels increase when it is dark and rise about two hours before sleep. Light at night can lower the amount you make, and blue light, including from phones, tablets and computers, can reduce or delay melatonin in the evening.
In Australia, people aged over 55 can buy a slow-release form of melatonin over the counter, and all other people need a prescription. It is usually used for short-term sleep problems, or to reset the body clock after shift work or jet lag.
Connections
3 connections on the map. Select a topic to read its page.
Melatonin is controlled by
In the evening, the master clock tells the brain to make more melatonin, causing sleepiness.
Sources: National Institute of General Medical Sciences (NIH), Circadian rhythms; healthdirect Australia, Melatonin
Melatonin supports
Melatonin helps get your body ready for sleep, and its levels rise about two hours before sleep.
Melatonin has been studied for
- Trouble sleeping Supported
Melatonin can help reset your body clock after jet lag or shift work, but there is not enough strong evidence for long-term insomnia.
Sources: healthdirect Australia, Melatonin; NIH NCCIH, Melatonin: what you need to know
Sources
Each connection above names its own source. See every source AskBioMap uses.
Summarised from healthdirect and the NIH. Sources read on 13 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.