The quickest way to get over jet lag after arriving in Thailand is to start living on local time: get daylight during the day, stay awake until a reasonable local bedtime and avoid long daytime naps. Jet lag usually improves within a few days as your internal body clock adjusts to the new time zone.
For travellers arriving from Europe or North America, the large time difference can make the first few days particularly difficult. Planning before your flight and managing light, sleep and caffeine after arrival can help reduce jet lag symptoms.
What Causes Jet Lag When You Cross Time Zones?
Jet lag happens when you travel quickly across multiple time zones and your circadian rhythm remains aligned with the time at home.
Your circadian rhythm is your body’s internal clock. It helps regulate when you feel awake and when you feel ready to sleep, influenced strongly by light and darkness.
After a long flight to Thailand, the local time may say it is morning while your body still thinks it is the middle of the night. You may therefore feel exhausted during the day but find it harder to fall asleep when you go to bed.
According to the US Centers for Disease Control and Prevention (CDC), jet lag usually occurs when travelling across more than three time zones, although anyone crossing multiple time zones can experience it.
The more time zones you cross, the greater the potential impact of jet lag.
What Are the Symptoms of Jet Lag?
Jet lag is a temporary sleep disorder, but its effects aren’t limited to sleep.
Common symptoms of jet lag include:
- Difficulty falling asleep or waking at the right time
- Daytime tiredness and exhaustion
- Poor sleep quality
- Difficulty concentrating or remembering things
- Digestive problems
Some people also experience changes in appetite, nausea, constipation or changes in mood.
Symptoms commonly appear within the first day or two after travelling. How strongly you experience jet lag depends on factors including the number of time zones crossed, your normal sleep pattern and the direction in which you travelled.
Is Jet Lag Worse Travelling East or West?
Travelling east is generally harder on the body clock than travelling west.
When you travel east, your body needs to move its sleep-wake cycle earlier. If you travel west, you need to delay it. For most people, delaying the internal clock is easier than advancing it.
This matters for Thailand.
Travellers arriving from the UK and much of Europe have travelled east across several time zones, which can make jet lag more noticeable. You may become sleepy unusually early or late, wake at strange times and struggle to remain alert during the Thai daytime.
The reverse journey can produce a different pattern because you’re travelling west.
Jet Lag Remedies After You Arrive in Thailand
There is no instant jet lag cure. The aim is to help your body clock synchronise with Thailand’s local time as efficiently as possible.
Get daylight
Light exposure is one of the strongest signals controlling your circadian rhythm.
Going outside during daylight can help your internal clock adjust to the new schedule. The timing of light exposure matters, particularly after very large time zone changes, so more light is not necessarily better at every hour of the day.
Switch to Thailand time
Try to eat, sleep and wake according to local time as soon as practical.
If you arrive during the day, resist the temptation to go straight to bed for several hours. Staying awake until a reasonable local bedtime can make it easier to adjust to the new time.
Keep naps short
If you’re struggling to stay awake, the CDC recommends keeping daytime naps to around 15–20 minutes.
A short nap can make you feel more alert without taking away too much of the sleep pressure you’ll need to fall asleep that night.
Drink plenty of water
Drink water regularly during your flight and after you arrive.
Hydration won’t reset your body clock, but feeling dehydrated on top of being tired can make a long journey considerably less comfortable.
Use caffeine carefully
Caffeine can help you remain alert during the daytime, but timing matters.
Coffee late in the afternoon or evening can make it harder to sleep when your body is already struggling to adjust. The CDC recommends using caffeine strategically and avoiding it in the evening.
How Can You Reduce Jet Lag Before a Long Flight?
Some jet lag remedies work better when you start before getting on the aircraft.
If possible, begin shifting your sleep schedule towards your destination a few days before travelling. The CDC suggests going to bed an hour or two earlier when travelling east and an hour or two later when travelling west.
Getting plenty of rest before departure also matters. Starting a long flight already sleep-deprived can make jet lag symptoms worse.
During the flight, try to think in terms of your destination rather than the place you left. If it is nighttime in Thailand, try to sleep. If it is daytime, staying awake can help begin the adjustment.
For an important meeting, event or activity soon after arrival, the CDC recommends considering arrival at least two days beforehand to give your body time to adapt.
What Makes Jet Lag Worse?
One of the easiest mistakes is sleeping for several hours during the day after arriving.
It may feel good at the time, but a long afternoon sleep can leave you wide awake during the night and delay your adjustment to the new time zone.
Other things that can make jet lag worse include excessive caffeine late in the day, drinking too much alcohol, starting your journey without enough sleep and repeatedly switching between your home schedule and Thailand time.
Trying to force yourself to sleep with sleeping pills or other sleep aids without appropriate medical advice isn’t a good substitute for allowing your body clock to adjust.
How Long Does Jet Lag Last?
Jet lag usually improves within a few days, although the duration varies between travellers.
The number of time zones crossed, direction of travel and individual circadian rhythm all influence how quickly you adjust. Someone travelling to Bangkok from a neighbouring Asian country may experience little or no jet lag, while someone arriving from Europe or North America has crossed considerably more time zones.
Rather than relying on a fixed formula of one recovery day for every time zone crossed, look for gradual improvement in your sleep, daytime alertness and ability to function normally.
If you are still feeling significantly unwell after several days, it is worth considering whether jet lag is actually the only cause.
Can Melatonin Help With Jet Lag?
Melatonin is a hormone produced naturally by the body that helps regulate the sleep-wake cycle. Synthetic melatonin is also used in some countries as a short-term treatment for sleep problems and jet lag.
Evidence and recommendations vary. UK NHS medicines guidance notes evidence that melatonin may reduce the severity and recovery time of jet lag in adults, while general NHS jet lag guidance says medicines are not usually necessary.
Timing is also important. Taking melatonin at the wrong point in your circadian cycle may not have the intended effect.
If you’re considering melatonin or another sleep aid, particularly if you take other medication or have an existing health condition, speak to a doctor or pharmacist about whether it is appropriate for you.
When Is It More Than Jet Lag?
Jet lag should gradually improve as your body clock adjusts.
If your symptoms are severe, continue without improvement or are significantly affecting your ability to function, speaking to a doctor can help determine whether something else is going on.
This is particularly relevant after international travel because tiredness, sleep disturbance and feeling generally unwell aren’t unique to jet lag. Illness, dehydration, medication changes and existing sleep problems can produce some similar symptoms.
If you’re in Bangkok and aren’t improving as expected, a doctor can assess your symptoms rather than simply assuming your long flight is responsible.
[Book a Doctor Consultation at WellMed Bangkok Clinic →]
Getting Over Jet Lag in Thailand
For most travellers, time is the main jet lag cure. Your internal clock needs a chance to catch up with the new time zone.
Daylight, switching to local sleep and meal times, keeping naps short and using caffeine carefully can make the adjustment easier. If you’re travelling to Thailand for something important, arriving a couple of days early can also give your body valuable time to adapt.
If the fatigue or sleep problems aren’t improving within a few days, or you feel unwell in ways that don’t seem consistent with normal jet lag, consider speaking to a doctor.
About WellMed Bangkok Clinic
WellMed Bangkok Clinic provides medical care for residents, expats and visitors in Bangkok, with clinics in Asoke and Silom. Services include doctor consultations, health check-ups, blood tests, vaccinations, sexual health care and travel-related medical care.
If you become unwell while visiting Bangkok, or symptoms you assumed were jet lag are persistent or worsening, a WellMed doctor can assess your symptoms and advise on appropriate treatment or further care.
Frequently Asked Questions About Jet Lag
Jet lag affects people differently, but these are some of the most common questions travellers ask before and after a long flight.
How long does jet lag last from the UK to Thailand?
Jet lag after travelling from the UK to Thailand commonly takes several days to improve because the journey crosses multiple time zones in an easterly direction. Individual recovery varies depending on your sleep pattern, flight schedule and how quickly your body clock adjusts to Thailand time.
How do you get rid of jet lag after a flight?
Start following local time as soon as possible, get daylight during the day and try to stay awake until a reasonable local bedtime. Keep daytime naps short, drink plenty of water and avoid caffeine late in the day.
How do you beat jet lag returning from Asia?
When travelling west from Asia, begin following your destination’s sleep and waking times as soon as practical. Daylight, appropriate sleep timing and avoiding long daytime naps can help your internal clock adjust after you arrive.
What are the worst days of jet lag?
Symptoms are often most noticeable during the first few days after crossing multiple time zones. The exact pattern varies according to your journey and body clock, but sleep disturbance, fatigue and concentration problems should gradually improve as you adapt.
How long does it take to recover from jet lag?
Jet lag usually improves within a few days, according to NHS guidance. Longer journeys across several time zones can take more time, and individual recovery varies rather than following an exact number of days per time zone.
What are five symptoms of jet lag?
Five common symptoms are difficulty sleeping, daytime fatigue, poor sleep quality, difficulty concentrating and problems waking at the appropriate local time. Some travellers also experience digestive or mood changes.
What should you not do when jet lagged?
Avoid long daytime sleeps, excessive alcohol and large amounts of caffeine, particularly later in the day. These can interfere with sleep or make it harder to establish a normal schedule in your new time zone.
What drink helps with jet lag?
Water is the simplest choice because staying hydrated can help you avoid adding dehydration to the fatigue of a long journey. Caffeine can temporarily improve alertness but should be used carefully because drinking it later in the day can interfere with sleep.
Which direction is worst for jet lag?
Eastward travel is generally more difficult because your body has to advance its internal clock and sleep earlier. Westward travel requires delaying the body clock, which many people find easier.
Sources
- US Centers for Disease Control and Prevention (CDC) — Jet Lag, Travelers’ Health. Guidance on time zones, sleep adjustment, daylight, caffeine, hydration, naps and reducing the effects of jet lag.
- NHS — Jet lag. Guidance on symptoms, recovery, sleep schedules, daylight, hydration and when medicines may be considered.
- NHS — Common questions about melatonin. Information on the evidence for melatonin and jet lag in adults.
- Mayo Clinic — Guidance on circadian rhythm, eastward and westward travel, light exposure and adjusting to a new time zone.
