There are several things you can do to minimise the effects of jet lag.

When you arrive at your destination, you should:

• establish a new routine and try to get used to it as soon as possible – eat and sleep at the correct times for your new time zone, not when you usually eat and sleep at home
• avoid napping as soon as you arrive at your destination – even if you're tired after a long flight, try to stay active until the correct time to sleep; this will help your body adjust more quickly
• spend time outdoors – natural light will help your body adjust to a new routine

If you take medication, such as oral contraceptives or insulin, at specific times of the day, consult your GP or pharmacist before travelling. They'll advise you about when to take your medication after you arrive at your destination.

Melatonin

Melatonin is a hormone that your body releases in the evening. It lets your brain know it's time for your body to sleep.

Your body clock is controlled by natural daylight and by the melatonin released in your body.

Melatonin is produced when it gets dark to prepare your body for sleep. Your body stops producing the hormone when it gets light to help you wake up.

Some jet lag remedies contain melatonin to help you sleep at night when your body is finding it difficult to adjust to the new time zone. Melatonin is most effective when it's taken three hours before the time you want to fall asleep.

However, at the moment there's not enough evidence to say whether melatonin supplements are effective. Some people find them helpful, but they're not currently licensed in the UK for the prevention of jet lag.

There's also insufficient evidence regarding the possible side effects of melatonin for people taking the blood thinning medicine warfarin.

Speak to your GP if you're thinking about taking a jet lag remedy that contains melatonin. They'll be able to advise you about its suitability for you.

Sleeping tablets

Some people find taking sleeping tablets can help relieve jet lag. However, they're not usually recommended because they can be very addictive if used for more than a few days.

Sleeping tablets can also cause side effects such as:

• a runny nose
• headaches 
• diarrhoea

Buying medications online

You may be tempted to look for jet lag remedies online.

However, it is important to take great care when buying medicines over the internet, particularly if the medicine would normally only be available on prescription, as there is a risk of getting substandard or fake medicines that are not safe or suitable to use.

If you are thinking about buying what may be a prescription-only medicine, you should consult your doctor, rather than buy the medicine direct from an internet supplier without a prescription.

The Medicines and Healthcare Products Regulatory Agency (MHRA) has more information about buying medicines online.