How to Prevent Jet Lag Before and During Your Flight
How to prepare for a long-haul flight so jet lag is shorter and milder, from the days before you leave to the moment you land.
Part of our jet lag guide.
After a long flight: call 999 if you have chest pain or sudden breathlessness, and get urgent help for a painful, swollen calf or thigh. These can be signs of a blood clot. A fever after travelling to a malaria area needs a doctor the same day.
Key fact: Moving your bedtime by about an hour a day towards destination time, for 2 or 3 days before you fly, gives your body clock a head start.
Flying long-haul soon?
Most jet lag gets better with the right routine. If it badly affects you, our UK prescribers can assess you online for licensed jet lag treatment. Adults 18 and over. Approved before 3pm, Monday to Friday? Dispatched the same day, by Royal Mail Tracked 48, Tracked 24 or Special Delivery guaranteed by 1pm next working day.
Start Jet Lag Consultation →Can jet lag be prevented?
Not completely, if you're crossing several time zones: your body clock can only move so fast. But you can make jet lag shorter and milder by starting to adjust before you leave, using the flight well and switching to local time as soon as you land. This guide covers preparation; once you've arrived, see how to get over jet lag.
Adjust your sleep before you fly
For 2 or 3 days before you travel, move your bedtime and wake-up time by about an hour a day towards destination time:
- Flying east (e.g. to Asia): go to bed and get up an hour earlier each day, and get bright light in the morning.
- Flying west (e.g. to the USA): go to bed and get up an hour later each day, and get light in the evening.
Even a 1 or 2 hour head start makes the first days easier. Most importantly, don't start the trip short of sleep: avoid late nights packing and finish work early if you can.
Choose your flight with jet lag in mind
- Arrive in the early evening if you can, so you only need to stay awake a few hours until a normal local bedtime.
- For overnight flights, eat beforehand so you can sleep as soon as possible on board.
- Plan important meetings or events for a day or two after arrival, at times when you'll be most alert.
- On a long journey with a stopover, a break of a day may help you adjust in stages.
Flying east is usually harder than flying west, so it's worth more preparation. Our guide east vs west jet lag explains why.
On the plane
1
Switch to destination time
Set your watch and phone to local time at your destination when you board, and try to eat and sleep to match it.
2
Sleep if it's night where you're going
Use an eye mask, earplugs and a neck pillow. Try to stay awake if it's daytime at your destination.
3
Drink water
Cabin air is dry. Drink regularly, and go easy on alcohol and caffeine, which disrupt sleep.
4
Move around
Walk the aisle and stretch your legs regularly. This also lowers the risk of blood clots on long flights.
When you arrive
Switch to local time straight away: eat at local mealtimes, get outside in daylight, keep naps short and go to bed at a normal local time. Our guide how to get over jet lag covers the first few days in detail.
Short trips: stay on home time
If you're only away for 2 or 3 days, adjusting and then readjusting when you get home can leave you jet lagged twice. Instead, try to sleep and eat on UK time as much as you can, and plan important commitments for when you'd normally be awake at home.
Medicines to prevent jet lag
There are no medicines you need to take before you fly to prevent jet lag. Melatonin for jet lag is licensed to start after you arrive, at bedtime in your destination time zone, not before you travel. Our melatonin for jet lag guide explains how it's used, and our main jet lag guide covers other options.
Don't forget other travel health. Check whether you need malaria tablets for your destination, and if you get travel sick, see our travel sickness tablets.
When to get medical help
- Call 999 for chest pain, sudden breathlessness or coughing up blood during or after a flight.
- Get urgent help for a painful, swollen, warm or red calf or thigh after a long flight.
- Talk to your GP before a long flight if you've had a blood clot before, are pregnant, or have recently had surgery.
Getting jet lag treatment
If jet lag badly affects you on every trip, our UK prescribers can assess adults online for licensed treatment before you go. See our jet lag treatment page.
UK safety and reporting side effects
In the UK, melatonin is a prescription-only medicine. Melatonin 3mg tablets are licensed for the short-term treatment of jet lag in adults aged 18 and over, and they aren't licensed for jet lag in children. Before any medicine is supplied, a GPhC-registered pharmacist independent prescriber reviews your consultation, including your health and the other medicines you take. Always read the patient information leaflet in the pack.
Melatonin sold as a supplement abroad or on unregulated websites (as gummies, sprays or tablets) isn't a licensed medicine in the UK, and its strength and contents can vary. Only buy medicines from a registered UK pharmacy: you can check any online pharmacy on the GPhC register.
If you think you've had a side effect from a medicine, tell your pharmacist or doctor. You can also report it to the MHRA through the Yellow Card scheme, which helps keep medicines safe for everyone.
Jet lag is only one part of travel health. Before you go, check FCDO travel advice for your destination and TravelHealthPro for vaccines and malaria advice. Tiredness after a long-haul flight affects your reactions, so don't drive if you feel sleepy after you land.
Frequently Asked Questions
How can I avoid jet lag?
Start shifting your bedtime towards destination time 2 or 3 days before you fly, arrive well rested, sleep on the plane only if it's night at your destination, and switch to local time as soon as you land.
Should I sleep on the plane to avoid jet lag?
Sleep if it's night-time at your destination, and try to stay awake if it's daytime there. Setting your watch to destination time when you board makes this easier.
What time of flight is best for jet lag?
A flight that arrives in the early evening is often easiest, because you only need to stay awake a few hours before a normal local bedtime.
Should I stay up all night before a long flight?
No. Starting a trip short of sleep usually makes jet lag worse. Aim to be well rested before you travel.
How do I prepare for jet lag when flying east?
For a few days before you go, go to bed and get up an hour earlier each day, and get bright light in the morning. Flying east is usually the harder direction, so preparation helps more.
Can I take something before I fly to prevent jet lag?
No medicine needs to be taken before you fly. Melatonin for jet lag is licensed to start at bedtime after you arrive, and it's a prescription-only medicine in the UK.
References
- NHS. Jet lag. nhs.uk
- Centers for Disease Control and Prevention. CDC Yellow Book: Jet lag disorder. cdc.gov
- Melatonin 3 mg film-coated tablets: summary of product characteristics. medicines.org.uk
- NHS. Deep vein thrombosis (DVT). nhs.uk
Medical disclaimer: This article is for information only and isn’t medical advice. Prescription medicines, including melatonin, need a clinical consultation before they can be supplied. If you have chest pain, sudden breathlessness or a painful, swollen leg after a flight, seek medical help straight away. In a medical emergency, call 999.