# How do I get over jet lag faster?

> If it’s the small hours and you’re wide awake in a strange room, or lying beside someone fast asleep at home after a trip east, your body’s still keeping the hours of the place you left. It’s already on its way here.

**In short:** Jet lag is your body clock still keeping home time. It catches up by roughly an hour a day, faster after flying west than east, and light is what moves it. Which way it moves depends on whether the light comes before or after your body’s coldest, sleepiest hour. So when you get daylight matters more than how much, and the hours to seek it and the hours to stay dim move a little each day.

It’s 3:40am, the room is dark and a little too warm, and the city outside has gone silent. You’re completely awake, and already working out how many hours are left before the meeting, or the tour, or the morning everyone will expect you to be yourself. The hotel, or the house, is asleep around you.

## Why am I wide awake at 3am?

At 3am here it may be early evening at home, or the middle of the morning, depending on which way you flew. Your body’s still keeping those hours. The heavy, scratchy-eyed tiredness from a short night, dry cabin air and a cramped seat is travel fatigue, and it belongs to the flight and the hours just after it. Jet lag is what stays on in the days after you cross three or more time zones, because the body clock that times your sleep is still set to the place you left[^1][^2]. It moves toward local time a little each day[^3], and it’s already begun.

**If you’d like to try something now**

You could keep the room dark, the phone dimmed or face down, and leave the bright lobby until morning. After a long trip across many zones, whichever way you flew, light at this hour is likely to push the clock the wrong way[^1][^4]. There’s no need to make yourself sleep or count the hours. If you do get up, the lights can stay low[^1]. There’s more on [getting up in the night when sleep won’t come](https://nitez.com/getting-up-at-night).

## Why do I feel so foggy, and hungry at the wrong times?

Almost every system in the body keeps its own daily rhythm, so jet lag reaches well beyond sleep, into heavy eyes by day, trouble concentrating, a shorter temper and an unsettled gut. Your appetite and the clocks in your gut and liver keep their own time. They catch up at different speeds from the clock that times your sleep, so for a few days they’re out of step with each other as well as with the clock on the wall[^3][^5]. Hunger can go missing at local mealtimes. The toilet can call at hours that make no sense, and you may wake at night to pass urine.

At the center of it is the body’s coldest, sleepiest hour, the low point in core temperature that usually comes in the early hours before waking. Nobody can feel where theirs is, but your usual sleep tells you roughly when it comes. For someone who normally sleeps from 11pm to 7am, it falls at about 4am home time. It moves an hour earlier or later for every hour earlier or later you usually sleep. Sleepiness and slips of attention are at their worst in the two or three hours either side of it[^1][^4], so wherever that stretch falls in your new day is when you’ll feel foggiest. After flying from Los Angeles to London, eight hours east, that hour comes around midday local time. The late morning and early afternoon are when your eyes close mid-conversation, and bedtime comes while your body’s still in its afternoon. Going the other way, London to Los Angeles, it comes at about 8pm, and you fade through the evening and wake far too early[^1].

## Is it safe to drive after a long flight?

After an overnight flight, please arrange a ride from the airport if you can. For the first few days, keep any drives away from the hours when your eyes close on their own: after a big trip east, that’s the late morning and early afternoon[^1]. A US study looked at everyday drivers in crashes, rather than travelers. Those who’d slept under four hours in the day before were about fifteen times as likely to have caused their crash as those who’d slept seven to nine. A recent change in sleep schedule was linked to causing crashes too[^6]. A long flight tends to bring both at once: a short night and a schedule turned around.

## Why is the second night worse than the first?

The first night often goes better than you feared, and then the second or third comes apart. On that first night sheer lack of sleep pulls you under, whatever the clock says. That debt can largely be made up within a day. What it leaves behind is the clock, which moves far more slowly. The symptoms are worst while its low point still falls in your waking day[^4]. In one worked example of a trip nine hours west, from San Francisco to Beijing, the night predicted to be hardest for staying asleep was the second[^4].

For some people it runs longer still. In one small study, people flew seven hours east, took a dummy pill and had their sleep recorded night after night. Falling asleep grew harder from about the fourth night and stayed that way through the eighth. By day they were still dropping off in under ten minutes on nap tests for all ten days they were followed[^7]. If your fourth night is harder than your first, it was the same for the people in that study.

## Why is flying east so much harder?

Flying east asks your body clock to move earlier, and flying west asks it to move later. Left to itself, the human clock runs a little longer than a day, about 24.2 hours on average. So it drifts later easily and resists being pulled earlier, which is why recovery after eastward flights takes longer[^4][^1]. Early measurements in travelers found the clock moving about ninety-two minutes later each day after flying west, and about fifty-seven minutes earlier each day after flying east[^4][^3].

That’s where the old rule of a day per time zone comes from, and as an average it’s about right. People vary a good deal around it, and the clock is usually quicker at the start than near the end[^3][^4]. Perhaps a third of travelers don’t get jet lag at all[^3].

After a long trip east, especially eight time zones or more, the clock often goes the long way round instead. In one study, eight people flew eleven time zones east, and seven of them adjusted by moving later. Why would a clock travel nearly all the way round the world rather than take the short way back? A likely reason is the same tendency that makes east hard in the first place: a clock that drifts later easily and resists being pulled earlier may find it easier to keep sliding later than to be dragged back. In another small group flying eight zones east, one person’s clock hadn’t shifted at all after five days[^4][^3]. These are only a handful of people, but they show how a long trip east can linger.

## When will daylight help, and when is it better to stay dim?

Light is what moves the body clock, and which way it moves depends on when the light reaches you. Light in the twelve hours or so before your body’s coldest hour pushes the clock later. Light in the twelve hours or so after it pulls the clock earlier. That’s why the same bright morning can move you toward home time after one trip and further from it after another. The effect is strongest in the three to six hours either side of that hour, and those are the hours worth planning around. Brighter, longer and bluer light makes them count for more. Through the middle of your body’s day you can live as you like, since bright light then has little effect[^1][^4].

Daylight outdoors is far brighter than any room, so when you want light, being outside without sunglasses gives you the most of it. When you want to keep it away, you could stay indoors with the lights low, or wear wraparound sunglasses that let little through. Either way, those hours pass without pushing the clock the wrong way[^1][^4].

You may already have tried staying up until local bedtime. It lines your sleep up with the new night, and the sleep you’ve lost helps pull you under, at least on the first night[^4]. The clock itself moves more slowly, with light doing most of the steering. You can hold out until 11pm and still wake at 3am while your coldest hour is still in the local day[^4][^1]. So it helps to ask each day where that hour falls now. You could start from where it falls at home (about 4am, if you usually sleep 11pm to 7am) and work out what time that is where you are. From there it travels toward the local night by something like an hour a day[^1][^3]. As the hour moves, the windows on either side of it move too, so the light you were keeping out yesterday morning may be the light you want today.

**Where your coldest hour sits, day by day, after nine zones west and east**

Read down the days: going west the hours to seek daylight drift later into the evening, and going east they slide earlier through the morning, a little each day. This is a modelled example[^1] for someone who usually sleeps 11pm to 7am, lands at 1pm and follows a timed plan of light and melatonin. The windows are the hours either side of the coldest hour[^1][^4] where light moves the clock most. Real clocks vary.

16:00

Your coldest hour

Where it ends up

04:00

Asleep

23:00

07:00

Seek daylight

Stay dim

- **After nine zones west**

- **After nine zones east**

**Get out in the sun as soon as you land.**

Daylight is the strongest signal the body clock has, and after flying west, soaking up as much of it as you can works well[^1][^3].

Which way light moves the clock depends on when it reaches you. After a big trip east, morning light can fall before your body’s coldest hour and push the clock later, while afternoon light pulls it earlier, so a whole day in the sun can cancel itself out. After eight hours east, the better plan is to avoid sunlight before midday and get as much as you can in the three to six hours after[^1][^3]. This is reasoned from laboratory measurements and fits the models well, though the data from travelers that directly support it are very limited[^7].

- Your coldest hour now falls in the local evening, about 10pm after six zones west and 7pm after nine. The light that helps is the late afternoon and evening light just before it, which pushes the clock later, the way it needs to go. The early morning, when you wake too soon, is the time to keep dim, since light then would pull you back[^1][^4]. In the modelled plan in the figure, with light and melatonin, after nine zones west the coldest hour is back inside the night by about the third day and fully home by the seventh[^1].

- Your coldest hour now falls in the local daytime, about 7am after three zones east, 10am after six and 1pm after nine. The light that helps is in the hours just after it[^1]. After a short trip that means morning light; after a long one it means keeping the morning dim and going out into the afternoon. If your morning’s your own, that can be indoors. If it belongs to a meeting, a tour or the children, wraparound sunglasses let you be out in it while little of the light gets through[^1][^4]. In the same modelled plan, after nine zones east the coldest hour is back inside the night by about the fifth day and fully home by the eighth[^1].

**How well have these light plans been tested in real travelers?**

In the one controlled field trial of light in the jet lag guideline’s evidence review, people flew west from Zurich to New York and wore a light visor for two evenings. Their clocks moved, but their symptoms stayed the same[^7]. The reviews since tell a similar story. One gathered thirteen studies with a control or comparison group, all testing non-drug jet lag treatments in real air travel. Nine found no significant effect, three were mixed and one was positive, and the authors put this down mostly to poorly designed interventions. Another, of studies in athletes, rated the evidence as low quality[^8][^9].

The laboratory side is solid. Measurements in healthy adults of how light at each hour moves the clock are consistent across reviews[^1][^4]. What researchers don’t agree on yet is how much of that works on a real trip. The day-by-day timelines in the figure are modelled, and their authors call for field trials[^1]. The researchers who designed such plans think the time you land and the light you happen to meet in the first days explain much of what travelers credit to their own habits. They also point out that apps and products offering light schedules can give opposite instructions, most of them assuming the clock moves earlier far faster than it does[^4].

That still leaves a light plan looking like a low-cost bet. The laboratory timing is solid, it costs you little more than choosing when to go outside, and nobody yet knows how well it works on a real trip. It’s worth following loosely, around your own coldest hour, without expecting it to guarantee a quick recovery.

## Is it worth adjusting for a trip of only a day or two?

For a stay of two days or less, the US guideline on jet lag suggests keeping your home sleep hours[^2] rather than switching to local ones. The study behind that advice followed people on a two-day layover after flying nine hours west. Those who kept home hours were less sleepy and had less jet lag. They did face a longer stretch awake around the flight home, 37.5 hours against 30.6, and a third of them preferred living on local time so they could fit in with meals and evenings[^7][^3]. It’s the guideline’s lowest grade of advice, based on that one study. That leaves it a choice to make around what the trip is for: the morning meeting your home clock can manage, or the dinner you came to share.

## Is it okay to nap, and what about coffee?

It’s easy to lie down for a quick nap in the afternoon and wake three hours later into a second wakeful night. A nap can still get you through the worst of the afternoon, and kept to about an hour it doesn’t eat into the night ahead[^1][^4]. If you can, it fits best in a stretch when you’d be keeping out of the light anyway. There’s more on timing in [Are naps good for you?](https://nitez.com/are-naps-good-for-you)

Caffeine can take the edge off the daytime sleepiness, and the guideline lists it as an option, though it may cost you some of the night. In two small trials after a seven-hour flight east, slow-release caffeine made people measurably less sleepy by day, but they took longer to fall asleep and woke more often at night[^2][^7]. It reaches the clock as well: in one laboratory study, a single evening dose pushed it about three hours later[^3]. Ordinary coffee hasn’t been studied in a controlled way[^7] for jet lag. If you reach for a cup, you could keep it to the earlier part of your new day, with [how long caffeine stays in your system](https://nitez.com/caffeine-and-sleep) in mind.

## Does it help to eat at local mealtimes?

Meals are a weaker time signal than light, and they speak mostly to the clocks in the gut and liver. You could eat at ordinary local times, which is likely to help those clocks fall in line, though there are no large trials[^3]. In a laboratory study, ten young men had their meals moved five hours later. Over thirteen days the daily rhythm of their blood sugar shifted by about 5.7 hours, while the master clock stayed where it was[^5].

The “feast and fast” anti-jet-lag diet grew from this idea, and it gives you something to do on a trip where so much is out of your hands. Its only field test, in 186 soldiers flying nine hours west, reported fewer symptoms[^7]. But the soldiers chose for themselves whether to follow it, no one was clearly checking and the symptoms were their own reports. Fewer of them chose it on the way home[^7], and the diet remains unproven.

## Does melatonin help with jet lag?

Perhaps you took melatonin from an airport pharmacy at whatever hour seemed sensible, and couldn’t tell whether it did anything. Melatonin does help when it’s taken at the right time. Researchers gathered ten trials in people flying across five or more time zones, and nine of them found it reduced jet lag. About one in every two people who took it benefited[^10], probably more so the more zones they crossed, and less going west. The reviewers recommend it particularly for trips of five or more zones east[^10].

So why might your packet have seemed to do nothing? Melatonin is the body’s own signal that night has come, and taken as a supplement it can nudge the clock along. It makes people sleepy mainly when it’s taken during the body’s daytime[^3][^1]. Taken at the wrong time, early in the day, it can cause sleepiness and slow your adjustment to local time[^10]. The hour you took it may well be why it did so little. Timed well, it earns the American Academy of Sleep Medicine’s “Standard”, its strongest grade for jet lag[^2].

For most adults, occasional short-term use for jet lag appears safe. If you have epilepsy or take warfarin, please ask a doctor first, because case reports suggest it may cause harm[^10] in both. In the US it’s sold as a supplement and isn’t regulated by the FDA as a drug[^2]. [Is it okay to take melatonin every night?](https://nitez.com/melatonin) covers how much to take and when.

## How can I make the next trip easier?

If you can spare a few evenings before flying east, shifting a little at home lets the clock start moving before you leave. In a laboratory test, twenty-six young adults moved their bedtime and waking earlier for three days, with bright light each morning, some by an hour a day and some by two. An hour a day turned out to be enough. Those people’s clocks moved nearly an hour and a half earlier. The two-hour group’s moved little further, because their faster plan outran the clock and left them struggling to fall asleep by the third night[^11]. Nobody flew anywhere, so it hasn’t been tried on a real trip, though the guideline lists it as an option that may lessen jet lag[^2]. The researchers who designed it think even one or two days are likely to help, the main cost being the evenings you miss with family and friends[^4][^1]. Going west, the same idea runs the other way, with bed and waking thirty to sixty minutes later each day and light in the evening, though no studies have tested it for westward trips[^4][^1][^7].

The flight you choose may matter too. In one case series of eighty-five people flying ten time zones east, those who arrived around midday had fewer jet lag symptoms than those who arrived in the morning, perhaps because of when they first met daylight[^7].

**If you’d like to try something before you fly**

For a trip east, you could move your bedtime and waking an hour earlier for the last two or three days at home, with bright light each morning, and look for a flight that lands toward the middle of the day. For a trip west, the same plan runs the other way, with later nights and light in the evening.

Everyone’s coldest hour falls at a slightly different time and moves at its own pace, so the times given for an 11pm to 7am sleeper are a worked example to adjust to your own sleep.

- **Jet lag comes from the body clock still keeping home time in the days after crossing three or more time zones, apart from the tiredness of the flight itself.** well-established

- **Flying east is harder because the clock drifts later easily and resists being pulled earlier.** well-established

- **Light moves the clock later or earlier depending on whether it comes before or after the body’s coldest hour.** well-established

- **Melatonin taken at the right time reduces jet lag after crossing five or more time zones, most of all going east.** well-established

- **The clock usually catches up by roughly an hour a day, faster after flying west than east.** good-evidence

- **One study suggests that on a stay of two days or less, keeping home hours can mean less sleepiness, at the cost of a longer stretch awake around the flight home.** early-evidence

- **Moving sleep earlier for a few days before flying east shifts the clock in the laboratory; it hasn’t been tested on real trips.** early-evidence

- **Small trials suggest caffeine eases daytime sleepiness after a flight east and can disturb the night that follows.** early-evidence

- **It isn’t clear yet how well timed light plans work in real travelers, as field trials have been few and their findings differ.** still-debated

- **Little or no research has tested extra water, grounding or special glasses as jet lag treatments, and the feast-and-fast diet has had only one field test, which left it unproven.** not-well-studied

- **Will a drink on the plane help me sleep?** Alcohol helps you drop off, though it breaks up the second half of the night, the part of sleep that jet lag has already made fragile[^12][^7]. Whether it makes jet lag itself worse hasn’t been properly studied[^7]. Please don’t mix alcohol with sleeping pills on a trip, as together they’re a particular risk[^7]. There’s more in [Does alcohol help you sleep?](https://nitez.com/alcohol-and-sleep)

- **Should I take a sleeping pill?** Sleeping pills can help you sleep after a long trip, though they don’t move the body clock and haven’t been shown to lift the daytime fog, which still comes around your body’s coldest hour[^2][^4]. They have side effects too, including rare reports of memory blackouts[^2] when taken for travel. [Are sleeping pills safe to take?](https://nitez.com/sleeping-pills) goes through them.

- **Does jet lag get worse as you get older?** Researchers don’t agree yet on this one. Two small field studies, of eighty-five travelers and of thirty-three pilots, found older people reported somewhat fewer symptoms, while laboratory work and expert reviews suggest older people adjust less easily[^7][^3][^4] and find it harder to sleep at the wrong body-clock time.

- **Do jet lag apps, special glasses or drinking lots of water help?** Apps that tell you when to seek light can give opposite instructions, and most assume the clock moves earlier far faster than it does[^4], so it can help to check their advice against your own coldest hour. Drinking extra water, grounding and special glasses haven’t been studied as treatments for jet lag[^7][^4], so there isn’t much to go on yet either way.

- **Is jet lag bad for my health?** Jet lag is usually harmless and passes on its own[^7][^3]. The longer-term problems linked to a disrupted body clock come mostly from studies of shift workers, who spend years out of step, rather than from people who travel now and then.

## When will I start to feel like myself again?

You’re likely to feel better well before the clock is all the way home. Once your body’s coldest hour slips inside the hours you sleep in the new place, sleep tends to come longer and better, and the daytime fog lifts a good deal. Full adjustment takes several more days[^1]. Each day you spend in the right light and the right dark brings that hour a little closer to your night. Tonight, or whatever’s left of it, the dark room is already doing its part.

## Related questions

- [What is the body clock, and how does it decide when I’m sleepy?](https://nitez.com/body-clock)
- [How does light affect my sleep?](https://nitez.com/light-and-sleep)
- [Is it okay to take melatonin every night?](https://nitez.com/melatonin)
- [Are naps good for you?](https://nitez.com/are-naps-good-for-you)
- [How long does caffeine stay in your system?](https://nitez.com/caffeine-and-sleep)
- [How do I get through the day after a bad night?](https://nitez.com/after-a-bad-night)

## Sources

[^1]: Roach GD, Sargent C. Interventions to Minimize Jet Lag After Westward and Eastward Flight. Frontiers in physiology. 2019;10:927. [PubMed](https://pubmed.ncbi.nlm.nih.gov/31417411/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC6684967/) · [DOI](https://doi.org/10.3389/fphys.2019.00927)
[^2]: Morgenthaler TI, Lee-Chiong T, Alessi C, Friedman L, Aurora RN, Boehlecke B, et al. Practice parameters for the clinical evaluation and treatment of circadian rhythm sleep disorders. An American Academy of Sleep Medicine report. Sleep. 2007;30(11):1445–59. [PubMed](https://pubmed.ncbi.nlm.nih.gov/18041479/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC2082098/) · [DOI](https://doi.org/10.1093/sleep/30.11.1445)
[^3]: Arendt J. Approaches to the Pharmacological Management of Jet Lag. Drugs. 2018;78(14):1419–1431. [PubMed](https://pubmed.ncbi.nlm.nih.gov/30167980/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC6182450/) · [DOI](https://doi.org/10.1007/s40265-018-0973-8)
[^4]: Eastman CI, Burgess HJ. How To Travel the World Without Jet lag. Sleep medicine clinics. 2009;4(2):241–255. [PubMed](https://pubmed.ncbi.nlm.nih.gov/20204161/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC2829880/) · [DOI](https://doi.org/10.1016/j.jsmc.2009.02.006)
[^5]: Wehrens SMT, Christou S, Isherwood C, Middleton B, Gibbs MA, Archer SN, et al. Meal Timing Regulates the Human Circadian System. Current biology : CB. 2017;27(12):1768–1775.e3. [PubMed](https://pubmed.ncbi.nlm.nih.gov/28578930/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC5483233/) · [DOI](https://doi.org/10.1016/j.cub.2017.04.059)
[^6]: Tefft BC. Acute sleep deprivation and culpable motor vehicle crash involvement. Sleep. 2018;41(10):zsy144. [PubMed](https://pubmed.ncbi.nlm.nih.gov/30239905/) · [DOI](https://doi.org/10.1093/sleep/zsy144)
[^7]: Sack RL, Auckley D, Auger RR, Carskadon MA, Wright KP, Vitiello MV, et al. Circadian rhythm sleep disorders: part I, basic principles, shift work and jet lag disorders. An American Academy of Sleep Medicine review. Sleep. 2007;30(11):1460–83. [PubMed](https://pubmed.ncbi.nlm.nih.gov/18041480/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC2082105/) · [DOI](https://doi.org/10.1093/sleep/30.11.1460)
[^8]: Bin YS, Postnova S, Cistulli PA. What works for jetlag? A systematic review of non-pharmacological interventions. Sleep medicine reviews. 2019;43:47–59. [PubMed](https://pubmed.ncbi.nlm.nih.gov/30529430/) · [DOI](https://doi.org/10.1016/j.smrv.2018.09.005)
[^9]: Janse van Rensburg DCC, Jansen van Rensburg A, Fowler P, Fullagar H, Stevens D, Halson S, et al. How to manage travel fatigue and jet lag in athletes? A systematic review of interventions. British journal of sports medicine. 2020;54(16):960–968. [PubMed](https://pubmed.ncbi.nlm.nih.gov/32303523/) · [DOI](https://doi.org/10.1136/bjsports-2019-101635)
[^10]: Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. The Cochrane database of systematic reviews. 2002(2):CD001520. [PubMed](https://pubmed.ncbi.nlm.nih.gov/12076414/) · [DOI](https://doi.org/10.1002/14651858.CD001520)
[^11]: Eastman CI, Gazda CJ, Burgess HJ, Crowley SJ, Fogg LF. Advancing circadian rhythms before eastward flight: a strategy to prevent or reduce jet lag. Sleep. 2005;28(1):33–44. [PubMed](https://pubmed.ncbi.nlm.nih.gov/15700719/) · [PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC1249488/) · [DOI](https://doi.org/10.1093/sleep/28.1.33)
[^12]: Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research. 2013;37(4):539–549. [PubMed](https://pubmed.ncbi.nlm.nih.gov/23347102/) · [DOI](https://doi.org/10.1111/acer.12006)

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https://nitez.com/jet-lag · What helps · updated 2026-10-05