Melatonin for jet lag: dose, timing and which trips it helps

By the Gummy Verdict editorial team. Updated October 8, 2026.

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Of all the reasons people take melatonin, jet lag is the one the research supports best. A Cochrane review of the trials called melatonin “remarkably effective” at preventing or reducing it. That makes jet lag a good fit for a melatonin gummy, provided you take it at the right time. Taken at the wrong time, it can make things worse.

What jet lag is

Your body runs on an internal clock of roughly 24 hours, set mainly by light. It controls when you feel sleepy and alert, when you get hungry and when body temperature rises and falls. When you fly across several time zones, your internal clock stays on home time while the sun, meals and schedules around you follow local time.

The mismatch produces the familiar symptoms: wide awake at 3 am, exhausted at midday, poor concentration, stomach upset and a general feeling of being off. The clock adjusts on its own at a rate of roughly one time zone per day, and somewhat faster after westward flights.

Why direction matters

Most people find eastward travel harder. The body’s natural clock runs slightly longer than 24 hours, so staying up later comes more easily than falling asleep earlier.

Flying east, for example New York to Paris, you must fall asleep and wake earlier than your body wants. Bedtime arrives and you are not sleepy.
Flying west, for example New York to Los Angeles, you must stay up and sleep later. You get sleepy early and wake before dawn.

Melatonin is most useful for the first problem: falling asleep at a local bedtime that feels far too early.

What the research found

The Cochrane review pooled ten trials. Its main findings:

Melatonin reduced jet lag in eight of the ten trials when taken close to the target bedtime at the destination.
It works for flights crossing five or more time zones. The benefit was likely to be greater the more zones crossed, and smaller for westward flights.
Doses between 0.5 mg and 5 mg were similarly effective. People fell asleep faster and slept better after 5 mg than after 0.5 mg.
Doses above 5 mg appeared no more effective.
A 2 mg slow-release form was relatively ineffective, suggesting that a short, higher peak works better for this purpose.
Timing is critical. Taken at the wrong time, early in the day, it can cause sleepiness and delay adaptation.

The reviewers recommended it for adult travelers flying across five or more time zones, particularly eastward and particularly for those who have had jet lag before. They suggested that travelers crossing two to four zones could also use it if needed.

How much to take

Dose	What the research suggests
0.5 mg	Effective for shifting the body clock. Less sleep-promoting.
2 to 3 mg	A reasonable middle
5 mg	People fell asleep faster and slept better than on 0.5 mg
Above 5 mg	No added benefit

For most adults, 2 mg to 5 mg is the practical range. A gummy with 2.5 mg or 3 mg per piece is convenient, since one gives a moderate dose and two give about 5 mg. There is no reason to pack a 10 mg product for this.

If you have never taken melatonin, try it at home on an ordinary night first. You do not want to discover on a trip that it gives you a headache or leaves you groggy.

When to take it

This is the part that matters most.

The basic rule

After you arrive, take melatonin at bedtime in the new time zone, between about 10 pm and midnight local time, on the first night and for the next few nights. The trials used two to five days.

Flying east

On arrival day, stay awake until a normal local bedtime if you can. Get outside in daylight.
Take melatonin 30 to 60 minutes before the local bedtime.
Repeat for three to five nights, or until you are sleeping normally.
Get morning light at the destination. It pulls your clock earlier.

Flying west

Westward jet lag is usually milder and melatonin is less clearly useful. The typical problem is waking too early. Bedtime melatonin does not help much with that, and taking it in the early hours risks morning grogginess. Many travelers going west do well with light alone: stay outside in the late afternoon and early evening and go to bed at a normal local time.

Before you leave

Some specialists suggest starting to shift your schedule a few days ahead, going to bed an hour earlier each night before an eastward trip. Taking melatonin before departure requires more precise timing and is easier to get wrong. For most travelers, starting on the first night at the destination is simpler and is what the trials tested.

On the plane

Take it on the flight only if it is nighttime at your destination and you intend to sleep. Do not take it if you will need to be alert on landing, and never before driving.

Trips where it is not worth it

One to two time zones. Your body adjusts within a day or two.
Very short trips of two or three days across many zones. It can be easier to stay on home time than to shift twice.
Trips where you must be sharp shortly after waking, if you have found melatonin leaves you groggy.

Light matters more than melatonin

Light is the strongest signal to your body clock, and using it well does more than any supplement. The US Centers for Disease Control and Prevention’s travel guidance centers on light exposure and sleep scheduling.

After flying east: seek bright light in the morning and avoid it late in the evening.
After flying west: seek light in the late afternoon and evening and avoid bright light early in the morning.
Get outdoors. Daylight is far brighter than indoor lighting, even on an overcast day.
At night, keep the room dark and stay off bright screens.

For very large shifts of eight zones or more, the best times for light can be counterintuitive, and jet lag calculators or apps can work out a schedule.

Melatonin and light work together. Melatonin in the evening and light in the morning both tell the clock to move earlier, which is what an eastward traveler needs.

Other things that help

Caffeine in the local morning helps daytime alertness. Stop by early afternoon.
Short naps, under 30 minutes and not late in the day, take the edge off without wrecking the night.
Eat on local time.
Go easy on alcohol, on the flight and after. It fragments sleep.
Drink water. Cabin air is dry.
Set your watch to destination time when you board.

Traveling with gummies

Heat. Gummies soften and can melt together in a hot car or on a sunny windowsill. Keep them in your hand luggage, in their original bottle. See how to store gummy vitamins.
Local law. Melatonin is sold freely in the United States and requires a prescription in a number of other countries, including the United Kingdom, much of the European Union, Australia and Japan. Small quantities for personal use are usually tolerated, but rules vary. Check before you travel, and do not expect to buy it at your destination.
Keep the label. The original container shows what the product is.
Keep them away from children, including in hotel rooms and bags.

Who should not use it

The Cochrane reviewers noted two groups in particular who should avoid melatonin unless a doctor advises otherwise: people with epilepsy and people taking warfarin or other oral anticoagulants. In addition:

Pregnant or breastfeeding women.
People taking blood pressure or diabetes medication, immunosuppressants or sedatives.
Anyone who will drive, fly a plane or operate machinery within several hours.
Children. Ask a pediatrician.

Occasional use for jet lag over a few nights is the situation where safety data are most reassuring.

A sample plan: New York to London

London is five hours ahead. An overnight flight lands in the morning, local time.

When	What to do
On the flight	Try to sleep. Skip the alcohol.
Arrival morning	Get outside in daylight. Have coffee if you want it. Stay awake.
Afternoon	A nap of 20 to 30 minutes at most, before 3 pm.
10 to 11 pm local time	Take 2 mg to 5 mg of melatonin, 30 to 60 minutes before bed. Dark room.
Next mornings	Up at a normal local time. Morning light.
Nights 2 to 4	Repeat the melatonin at local bedtime, then stop.

For the return flight west, most people need only light and a normal bedtime.

For more on dose and timing, see which melatonin dose makes sense and how long melatonin takes to work. All sleep reviews are on the sleep gummies page.

The short version

Jet lag is the best-supported use of melatonin.
It helps most on flights crossing five or more time zones, especially eastward.
Take 2 mg to 5 mg at local bedtime at the destination for a few nights. More than 5 mg adds nothing.
Timing is critical. Taken at the wrong time of day it can slow your adjustment.
Daylight at the right time does more than any supplement.
Check the law at your destination and keep gummies cool.

Common questions

How much melatonin should I take for jet lag?

Trials found 0.5 mg to 5 mg effective, with better sleep on 5 mg than 0.5 mg and no added benefit above 5 mg.

When should I take melatonin for jet lag?

At bedtime in the destination time zone, starting on the night you arrive and continuing for two to five nights.

Does melatonin help flying west?

Less clearly. Westward jet lag is usually milder, and light exposure in the evening is the main tool.

Should I take melatonin on the plane?

Only if it is night at your destination and you plan to sleep, and you will not need to be alert soon after.

Is melatonin legal in other countries?

It is prescription-only in a number of countries. Check the rules for your destination before you travel.

How many time zones before jet lag is worth treating?

The research supports melatonin for five or more time zones, and suggests it can be used for two to four if needed.

Sources

These statements have not been evaluated by the Food and Drug Administration. Products discussed here are not intended to diagnose, treat, cure or prevent any disease. This page is not medical advice. It is written for adults 18 and over.