Jet Lag: 8 Simple Steps to Beat It Before, During and After Flying

Jet lag happens when you cross time zones faster than your body clock can follow. You land in the morning, local time, while your internal clock insists it is the middle of the night. The result is poor sleep, daytime tiredness and difficulty concentrating, and sometimes an upset stomach too. The good news is that the body clock responds to signals you can control, above all light and the timing of sleep, so a little planning can shorten the adjustment.

Updated September 2026.

This article is general information, not medical advice. Speak to a doctor or pharmacist before taking melatonin or any sleep medicine, especially as its legal status differs by country: it is sold as a dietary supplement in the US but is prescription-only in the UK.

What causes jet lag

The US Centers for Disease Control and Prevention (CDC) describes it as a temporary mismatch between your internal biological clock and local time after rapid travel across time zones. The NHS lists the main symptoms as trouble sleeping at bedtime and waking in the morning, tiredness and poor concentration, sometimes with indigestion, nausea, constipation or mild anxiety.

It usually improves within a few days as the body adjusts, according to the NHS. How many days depends on how far and in which direction you fly.

Why flying east is harder

The CDC’s Yellow Book gives rough adjustment rates: about 1.5 hours a day after westward travel, and about 1 hour a day after eastward travel. The reason is that most people’s natural body rhythm runs slightly longer than 24 hours, so it is easier to stay up later than to fall asleep earlier.

As a rough illustration of those rates, a six-hour shift eastward could take around six days to fully settle, while the same shift westward might take about four. Individual experience varies.

How to beat jet lag: 8 steps

1. Decide whether to adapt at all. The CDC suggests that for trips of under 2 days, it can make sense to stay on home time rather than trying to adjust.
2. Arrive rested. The NHS advises getting plenty of rest before you travel, since starting a trip short of sleep makes the adjustment harder.
3. Shift your schedule before departure. Gradually move bedtime and waking time towards the destination’s time zone in the days before you leave: earlier for eastward trips, later for westward ones.
4. Sleep on the plane only at destination night. Try to sleep when it is night where you are going, using an eye mask and earplugs.
5. Drink water and go easy on caffeine and alcohol. The NHS says both caffeine and alcohol can make symptoms worse, and the CDC notes that alcohol breaks up sleep.
6. Move around during the flight. The NHS recommends regular movement on board.
7. Use light deliberately. Light is the strongest signal to the body clock. The CDC explains that bright light in the morning pulls your clock earlier, while light in the evening pushes it later.
8. Switch to local time on arrival. Eat and sleep on the local schedule, set an alarm so you do not oversleep, get outside in daylight, and avoid daytime naps.

Using light the right way

Timing is what matters, and it depends on direction:

• After flying east: your clock needs to move earlier. Seek morning light at your destination and keep evenings dimmer.
• After flying west: your clock needs to move later. Get light in the late afternoon and evening, which helps you stay awake until a local bedtime.

Screens and in-flight entertainment are a mixed blessing here. A tablet late into what is night at your destination makes sleep harder, so plan your viewing, and if you intend to work on board, check how in-flight wifi works so you are not relying on it at a time you should be resting.

What health bodies say about melatonin

Melatonin is the hormone the body releases in the evening to signal night-time. Guidance on taking it for time-zone travel differs between countries:

• CDC (United States): the Yellow Book says doses of 0.5 to 1 mg can be effective and that doses above 5 mg are not recommended. It notes that melatonin is not regulated by the Food and Drug Administration, so the amount in a product may not match its label. Timing depends on direction of travel, which is another reason to get professional advice.
• NHS (United Kingdom): melatonin is available on prescription only. The NHS says it may help with symptoms, but its jet lag page states melatonin is not recommended on the NHS for this purpose because there is not enough evidence that it works.
• Elsewhere: rules vary, so check with a local pharmacist before buying it abroad or carrying it across a border.

A sample plan for an eastbound overnight flight

Suppose you are flying overnight from New York to London, a five-hour shift east:

1. For a few days before, go to bed and wake up a little earlier each day.
2. On board, eat early, then try to sleep for as much of the flight as you can.
3. On landing, stay awake, get outside in morning daylight and resist a nap.
4. Go to bed at a normal local time, with an alarm set for the morning.
5. Repeat morning light exposure for the next few days.

And for a westbound daytime flight

Flying from London to Los Angeles is an eight-hour shift west, where the aim is to stay up later rather than fall asleep earlier:

1. In the days before, push bedtime and waking time slightly later.
2. On board, stay mostly awake, since it is daytime at the destination.
3. On arrival in the afternoon, stay active and get outside in the evening light.
4. Hold out until a normal local bedtime, even if you feel sleepy early.

Using the CDC rate of about 1.5 hours a day for westward travel, a shift that size could take around five days to settle completely, although most people feel noticeably better well before then.

Getting to the airport calmly helps too: our guide on how early to get to the airport covers the check-in deadlines.

Common questions

How long does jet lag last? The NHS says it usually improves within a few days. The CDC estimates the body clock shifts about 1 hour a day after flying east and about 1.5 hours a day after flying west.

Is it worse flying east or west? East, for most people. The natural body rhythm runs slightly longer than 24 hours, so moving it later is easier than moving it earlier.

Should I nap when I arrive? The NHS advises avoiding naps during the day, so you can sleep at a normal local bedtime.

Does melatonin help with jet lag? Evidence is mixed. The CDC describes low doses as effective, while the NHS does not recommend it for this purpose. Ask a doctor or pharmacist, as it is prescription-only in some countries, including the UK.

Is it worth adjusting for a short trip? For trips of under 2 days, the CDC suggests staying on home time may be the better choice.

Sources and further reading

Where the figures and rules above come from, so you can check them:

• Jet lag disorder: adjustment rates, light and melatonin: CDC Yellow Book
• Jet lag symptoms and self-help: NHS
• About melatonin: UK prescription status: NHS

Photo credits: Airplane Window by World Travel Adventures, CC0, via Stocksnap. Indoor Airplane by Suhyeon Choi, CC0, via Stocksnap.