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Melatonin for jet lag: what the evidence says

What research says about melatonin for jet lag: how it works, the Cochrane review's findings on timing and dose, where it's sold, and when to ask a doctor.

By Surya Narayanan · · 3 min read · Sleep and jet lag

Melatonin is one of the better-studied aids for jet lag. A Cochrane review of the trials found that, taken close to local bedtime at your destination, it reduced jet lag for most travellers, especially after flying east across five or more time zones. It isn't a sleeping pill, it doesn't suit everyone, and the rules for buying it differ by country, so it's worth understanding before you try it, and checking with a doctor or pharmacist first.

This is general information, not medical advice. Melatonin can interact with other medicines; ask a doctor or pharmacist before using it, especially if you're pregnant, breastfeeding, have epilepsy, or take blood thinners such as warfarin.

What melatonin does

Melatonin is a hormone your brain releases in the evening, as light fades. It doesn't knock you out; it tells your body clock that night has arrived. Taken as a supplement at the right time, it can nudge the clock toward a new time zone and make it easier to fall asleep at the new bedtime.

What the evidence says

  • The main review. In 2002, Andrew Herxheimer and Keith Petrie reviewed ten trials for the Cochrane Collaboration. In nine of them, melatonin taken close to the target bedtime at the destination (roughly 10 PM to midnight) reduced jet lag after flights crossing five or more time zones.
  • Dose. Doses from 0.5 mg to 5 mg worked about equally well against jet lag, although people fell asleep a little faster on 5 mg. More than 5 mg didn't add anything.
  • Timing matters more than dose. Taken at the wrong time of day, melatonin can shift your clock the wrong way.
  • Side effects in the trials were uncommon and mild, such as drowsiness and headache.

How it's usually taken for jet lag

  1. On arrival, take it near local bedtime, typically for two to five nights.
  2. Combine it with the rest of the plan: light at the right time, local meal times, a fixed wake-up time.
  3. Don't drive or do anything that needs alertness for some hours after taking it.

Your doctor may suggest a different plan, such as starting before you fly; follow their advice over a blog post's. The jet lag calculator shows how far your clock has to move, and our day-by-day jet lag plan covers the non-drug side.

Buying melatonin

In the United States and some other countries, melatonin is sold as a dietary supplement, without a prescription. In the UK and many European countries it's a prescription medicine. Supplements aren't held to the same standards as medicines: when Lauren Erland and Praveen Saxena tested supplements bought in Canada, the melatonin content ranged from far less to several times more than the label said. If you buy it, a pharmacy brand with a verification mark is the safer choice.

When it's not worth it

  • For short trips where you'll stay on home time.
  • For time differences of a couple of hours, which most people adjust to within a day or two anyway.
  • If you have any condition or medication your doctor says it may affect.

Plan the time difference first

Before you think about any aid, know what you're dealing with: the time zone converter and jet lag calculator take a minute. And while you wait for the trip, Flight can fly the route at your desk as a focus session.

Questions

How much melatonin should I take for jet lag?

Ask a doctor or pharmacist for advice for you. In the trials reviewed by Cochrane, doses from 0.5 mg to 5 mg were similarly effective for jet lag, with 5 mg helping people fall asleep a little faster, and doses above 5 mg offered no extra benefit.

When should I take melatonin for jet lag?

In the studies, it was taken close to the target bedtime at the destination, roughly between 10 PM and midnight local time, for a few nights after arrival. Timing matters: taken at the wrong time, melatonin can shift your body clock the wrong way.

Is melatonin safe?

Short-term use appears to have few side effects for most healthy adults, mainly drowsiness and headache. It can interact with some medicines, including blood thinners, and isn't recommended for everyone, so check with a doctor or pharmacist first.

Is melatonin available without a prescription?

It depends on the country. It's sold as a supplement without a prescription in the United States and some other countries, but is prescription-only in the UK and many European countries.

Try it with a free tool

Keep reading

  1. How to get over jet lag: a day-by-day planHow long jet lag lasts, and a day-by-day plan to beat it: shift before you go, switch to local time on board, and use light, sleep and meals when you land.
  2. Red-eye flights: how to arrive restedHow to get the most sleep on an overnight flight and get through the day you land: when to book, what to skip on board, and how to handle arrival day.
  3. Sleep cycles explained: why 90 minutes mattersSleep runs in cycles of about 90 minutes through light, deep and REM sleep. What happens in each stage, why waking at a cycle's end helps, and how many you need.
  4. Caffeine half-life: when to have your last coffeeCaffeine's half-life is about five hours, so afternoon coffee is still working at bedtime. What's left of a cup over time, what changes it, and when to stop.