Supplement
Melatonin
A sleep-timing hormone that's useful for jet lag, less so as a nightly sleeping pill.
- Evidence
- Silver· human data
- Sources cited
- 1
- Last reviewed
- 22 July 2026
What it is
Melatonin is a hormone that signals "time for sleep" to your body clock. That makes it a body-clock tool more than a sedative, a distinction that explains where it works well and where it disappoints.
What the evidence shows
Jet lag and body-clock timing. Gold· human data Its strongest evidence is for shifting the body clock, jet lag and delayed sleep timing.
As a general sleeping aid. Silver· human data It can modestly help you fall asleep a bit faster, but it is not a powerful sleeping pill, and its long-term nightly use is not well studied.
Who it suits
Travellers crossing time zones and people whose sleep timing has drifted late, more than someone simply after a stronger nightly sedative.
Practical notes
Timing often matters more than amount: because it signals your body clock, when you take it is important, and lower amounts at the right time can work as well as larger ones. It is a hormone, so avoid it in pregnancy and seek medical advice for children or ongoing use, and note it is prescription-only in some countries. Sort your routine first with the sleep calculator.
Sources
Frequently asked questions
- Does melatonin help you sleep?
- Its strongest evidence is for shifting the body clock in jet lag and delayed sleep timing, rather than as a sedative. It can modestly help you fall asleep a bit faster, but it's not a powerful sleeping pill.
- Is timing more important than dose?
- Often, yes. Because it signals 'time for sleep' to your body clock, when you take it matters a lot, and lower amounts taken at the right time can work as well as larger ones.
- Is it safe to take every night?
- It's widely used short-term, but the long-term safety of nightly use isn't well established, and it's a hormone. It's best treated as a targeted tool rather than a default nightcap, with medical advice for ongoing use.