Patient information from BMJ

Jet lag

Last published:Dec 06, 2021

Jet lag can make you feel exhausted and spoil the first few days of a holiday or business trip. There are some simple self-help strategies that can help you cope with jet lag and feel better. A treatment called melatonin may also help.

We've looked at the best and most up-to-date research to produce this information. You can use it to talk to your doctor and decide which treatments are right for you.

Why do people get jet lag?

Jet lag is a side effect of long-distance air travel. When you travel by plane between different time zones, your body clock gets left behind in the place where you started. It can take a few days to catch up with you in your new time zone. So, for a while, your body tries to act as if you're still in the time zone of the place you travelled from. You may feel wide awake at night and sleepy during the day.

Your body clock is driven by daylight and a hormone in your brain called melatonin. Melatonin tells you when to sleep. Your body starts to make melatonin when it gets dark outside, and it stops when it gets light.

In general, the more time zones you cross, the worse your jet lag. For example, a flight from London to Los Angeles crosses eight time zones. This means the time in Los Angeles is eight hours behind the time in London. If you arrive in Los Angeles at 6 p.m., your body thinks it's 2 a.m.

As a rule, flying east seems to cause more problems for most people than flying west.

What are the symptoms?

The main symptom is tiredness, which can be severe. You might also have trouble sleeping and concentrating. And you may stop eating properly, have an upset stomach, and feel generally unwell.

What treatments work?

Jet lag gets better on its own after a few days. Some medicines can help you feel better faster. There are also some things you can try before and during your trip to minimise jet lag.

Things you can do for yourself

To help prevent jet lag

There are things you can do before your trip and during your flight that may help prevent or lessen jet lag.

• Your exposure to natural light plays a big role in helping you adjust to a new time zone. Before your trip, you might wear sunglasses to restrict your exposure to daylight when it would be dark at your destination. You might also try to go out in the daylight at times when it would be light at your destination.

• A few days before your trip, try to adjust your sleep and meal schedule to more closely match the schedule you will have at your destination.

• Make sure you are well rested before the start of your trip.

• During the flight, drink plenty of fluids but avoid alcohol and drinks with caffeine.

• Avoid sleeping during the flight unless it is night time at your destination.

• If your trip is short (three days or less), you might try to keep your schedule in the new time zone as close to your home schedule as possible, to avoid jet lag when you return. However, this may not be practical if you are crossing several time zones, or travelling for business.

To help get rid of jet lag

Once you've arrived at your destination, there are things you can try to cope with your jet lag and feel better faster.

• Avoid caffeine after midday at your destination, where it might interfere with sleep.

• Stay awake until it gets dark after a long trip going west. You might also try to book a flight that arrives at your destination at night.

• Get up when it gets light after a long trip going east. It may also help to be outdoors in sunlight during the afternoon.

• Eat small meals at the right mealtimes for your destination.

• Take some light exercise, such as walking or sightseeing, during daylight. But remember that exercising just before bedtime can sometimes make it harder to sleep.

Medicines

If your jet lag is more severe, taking melatonin tablets for a few days may help you feel better faster. The melatonin in the tablets is similar to the melatonin your body makes at night to help you sleep. You take these tablets when it's bedtime in your new time zone. People usually start taking them the day before their flight.

Melatonin is sold over the counter as a supplement in some countries (such as the US) but it is available only on prescription in others (such as the UK).

Another option is to take sleeping tablets at bedtime for the first few nights after you arrive in a new time zone. This may help you get over jet lag more quickly.

You shouldn't use sleeping tablets for more than a few nights. Taking them for longer can make you dependent on them. This means you can get unpleasant effects when you stop taking the sleeping tablets, such as anxiety. You may also have problems sleeping when you stop taking a sleeping tablet.

What will happen to me?

Jet lag is always at its worst soon after you arrive. The more time zones you cross, the longer it will take for your jet lag to wear off. Your body clock resets by about an hour each day if you've travelled eastwards, and about an hour and a half each day if you've travelled westwards.

Jet lag is inconvenient. But even without treatment, it usually lasts only a few days.