Melatonin

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. Well-supported· human data Its strongest evidence is for shifting the body clock — jet lag and delayed sleep timing.

As a general sleeping aid. Preliminary· 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

PubMed: melatonin supplementation, sleep onset, jet lag and circadian timing (reviews and trials)

Frequently asked questions

Does melatonin help you sleep?

Its strongest evidence is for shifting the body clock — 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.