Jet lag after long-haul flights: How do you overcome it fastest?

The holidays were wonderful – but the first week back feels like walking through cotton wool: wide awake at three in the morning, leaden with fatigue during the day, plus digestive problems and lapses in concentration. Jet lag is not imaginary; it's a tangible desynchronization: your internal clock is still on Bangkok or New York time, while your environment already demands Swiss time. Since the circadian rhythm shifts by only about 1 to 1.5 hours per day, adapting after a flight across 6 time zones can take up to a week if untreated. With the right strategy, this time can be roughly halved – primarily by adjusting the internal clock's most powerful lever: light at the right time. This article explains what happens in the body and provides a concrete plan for the days after landing.

The short answer: You can overcome jet lag fastest with targeted light timing: after westbound flights, seek light in the evening and go to bed late; after eastbound flights, get morning light and wake up early – for flights crossing more than 8 time zones to the east, even avoid morning light for the first 2 days. Additionally: eat and sleep immediately according to the destination's rhythm, limit naps to a maximum of 20 minutes, and, if necessary, take low-dose melatonin in the evening after consulting a doctor. Rule of thumb: about half to one day of adjustment per time zone – with a consistent light strategy, probably less.

What happens in the body: the internal clock in conflict

The suprachiasmatic nucleus, located in the hypothalamus, is the body's master clock, regulating sleep pressure, body temperature, cortisol and melatonin secretion, digestion, and even daily performance. This clock primarily synchronizes itself through daylight, which specialized receptors in the retina register. After a long-haul flight, the environment and the clock suddenly report conflicting times: cortisol rises at the wrong hour, melatonin comes at an inconvenient time, and digestive enzymes work at night. This explains the typical combination of symptoms including sleep disturbances, daytime fatigue, appetite shifts, and gastrointestinal issues. It's important to know: The organs also have peripheral clocks that adjust at different rates – which is why sleep might be fine while the stomach is still "eating in the old time zone." The basics of this are explained in the article on the internal clock and circadian rhythm.

East or West: why direction makes a difference

Flying west (e.g., to the USA) lengthens the day – and this is easier for the internal clock, because its natural rhythm is already slightly longer than 24 hours. You "only" have to stay awake longer and sleep later. Flying east (e.g., to Asia) shortens the day: you're supposed to sleep when your body still feels like it's afternoon – against the natural clock trend. As a rule of thumb: for westbound flights, expect about half a day of adjustment per time zone; for eastbound flights, up to a full day. A flight from Zurich to New York (6 time zones west) is therefore largely recovered from in 3 to 4 days, while a flight from Zurich to Tokyo (7 to 8 time zones east) can have lingering effects for almost a week. This asymmetry also determines the strategy: westbound travelers work with evening light and late bedtime, eastbound travelers with morning light and early waking – with one important exception for very large time jumps, more on that in a moment.

The light strategy: correctly using the most powerful tool

Light shifts the internal clock in two directions – depending on when it hits the retina. Light in the (biological) morning advances the clock, while light in the (biological) evening sets it back. Consequently: after westbound flights, actively seek light at your destination in the evening (stay outdoors, go for a walk) and avoid early morning light for the first few days – this shifts the clock backward. For eastbound flights up to about 8 time zones, the opposite applies: get out into daylight in the morning, dim lights in the evening, and avoid screens. Be careful with eastbound flights across more than 8 time zones: immediately after landing, your internal clock will still interpret the early morning light as "evening" and would shift in the wrong direction – therefore, avoid very early morning light for the first 2 days (sunglasses help) and instead get late morning light. Daylight outdoors provides 10,000 to 25,000 lux even on cloudy days – many times more than any indoor lighting. The article Blue Light and Screens in the Evening explains why screen light in the evening sabotages adjustment.

The concrete plan for the first few days

Day 0 (landing): Immediately set your watch to local time – mentally and on your wrist. Stay awake until local bedtime, no matter how difficult it gets; if necessary, take a power nap of a maximum of 20 minutes before 3 PM, as described in the article How to Take a Proper Power Nap. From now on, eat at local times – eating also helps adjust the organ clocks. Days 1 to 3: consistently wake up at the same local time (alarm clock!), apply the light strategy according to your flight direction, exercise outdoors during the day, avoid large meals and alcohol in the evening – alcohol further fragments already fragile adjustment sleep. Limit caffeine to before noon. In the evening, maintain a quiet routine with dimmed lights; if desired, use melatonin (see below). From day 3 to 4, sleep noticeably normalizes for most people; nevertheless, stick to fixed times until appetite and energy levels are also back in sync. And: do not schedule critical appointments for the first 48 hours after long-distance travel – reaction time and judgment are measurably reduced.

Melatonin, sleeping pills, and home remedies: what really helps?

Melatonin is the body's natural darkness signal – taken as a supplement at the right time, it can support clock shifting: typically low-dose (0.5 to 3 mg) about 30 to 60 minutes before the desired local bedtime, especially after eastbound flights. Studies show moderate but consistent effects on sleep onset time and perceived jet lag severity. In Switzerland, melatonin requires a prescription or is available in pharmacies depending on the dosage – clarify intake and dose with a doctor or pharmacist, especially if taking medication or pregnant. Traditional sleeping pills, however, are not a solution: they force sleep but do not shift the internal clock and can cause daytime grogginess. Proven supportive measures: a warm bath 1 to 2 hours before sleep (the subsequent drop in temperature makes you sleepy), a cool bedroom of 16 to 19 °C, and relaxation techniques like the 4-7-8 breathing method to combat nocturnal wakefulness – more on this in the guide Fall Asleep Faster.

Jet Lag Strategies at a Glance

Common mistakes after long-distance travel

Mistake one: sleeping for 3 hours in the afternoon on arrival day – this preserves the old time zone and costs you the following night. Mistake two: rushing into work immediately after returning home and sacrificing sleep further; this adds classic sleep deprivation to jet lag – how a deficit affects you and how to reduce it is shown in the article Catching Up on Sleep Deficit. Mistake three: staying awake in the evening under full artificial light and wondering why the clock isn't adjusting. Mistake four: liters of coffee as daytime support – late caffeine pushes falling asleep further back. Mistake five: the weekend trap, i.e., after overcoming jet lag, sleeping until noon on Saturday and thereby getting a homemade mini-jet lag. And mistake six: enduring jet lag in a bad bed – especially in the adjustment week, sleep is fragile, and a worn-out mattress with pressure points produces exactly the nocturnal awakenings you need least right now.

Frequently Asked Questions about Jet Lag after Long-Distance Travel

How long does jet lag last after a long-distance trip?

As a rule of thumb: after westbound flights, about half a day per time zone; after eastbound flights, up to one day per time zone. For 6 to 8 time zones, this means 4 to 7 days untreated – significantly less with a consistent light strategy.

Why is jet lag worse after eastbound flights?

Because the internal clock naturally runs slightly longer than 24 hours. Lengthening the day (westbound flight) is easier than shortening it (eastbound flight) – which is why adjustment takes longer when traveling east.

Does melatonin help with jet lag?

Studies show moderate, consistent effects: taken in a low dose (0.5 to 3 mg) 30 to 60 minutes before local bedtime, melatonin can support adjustment – especially after eastbound flights. Dosage and suitability should be discussed with a doctor or pharmacist.

Should I take a nap after landing?

Only briefly: a maximum of 20 minutes and not after 3 PM local time. Longer naps reduce too much sleep pressure and delay adjustment to the new time zone.

What role does light play in combating jet lag?

Light is the strongest pacemaker of the internal clock: morning light advances it, evening light sets it back. Correctly timed daylight – 10,000 to 25,000 lux outdoors – accelerates adjustment more effectively than any other single measure.

Can you reduce jet lag before the trip?

Yes. Shift your sleep and meal times by 30 to 60 minutes daily towards your destination time for 2 to 3 days before departure, and only sleep on the plane if it's nighttime at your destination. This gives your internal clock a head start.

This article is for general information purposes only and does not replace medical advice.