Jet Lag: A Practical Recovery Plan

Jet lag is not "tiredness from flying" — it is a temporary mismatch between your internal circadian clock and the local time at your destination. The body adjusts about 1 time zone per day eastward and 1.5 zones per day westward, so a New York → London trip naturally takes 5 days to resolve. With the right pre-trip plan and light strategy, you can cut that in half.

Everything below is organised around a single idea: your clock only moves when it receives a signal it recognises. Light is the loudest signal by a wide margin, melatonin is a quieter one, and meals, exercise, and social schedules are quieter still. Almost every jet-lag mistake is a case of sending the loudest signal at the wrong hour.

Eastbound vs. westbound — why direction matters

The human circadian system naturally runs slightly longer than 24 hours, which makes westbound travel (delaying your schedule) much easier than eastbound (advancing it). Eastbound flights force you to fall asleep before your brain is biologically ready, and the resulting "phase advance" is the hardest adjustment in chronobiology.

This asymmetry has a practical consequence: eastbound trips are won before departure, westbound trips are won after arrival. If you have limited willpower to spend, spend it on pre-shifting for eastbound flights and on staying awake until a sensible local bedtime for westbound ones.

Find your body clock's midpoint first

Light shifts your clock in opposite directions depending on when it lands relative to your core body temperature minimum — the coldest, sleepiest point of your night, which sits roughly two hours before your natural spontaneous wake time. Light after that point advances the clock (makes you earlier). Light before it delays the clock (makes you later).

So if you wake naturally at 7 AM on holiday, your temperature minimum is around 5 AM. Bright light at 6 AM pulls you earlier — useful eastbound. Bright light at 3 AM pushes you later — the opposite of what an eastbound traveller wants, and precisely what happens when you land in Europe at 6 AM local time (1 AM body time) and walk into a sunlit terminal. That single detail explains most "I did everything right and still felt destroyed" reports.

Three days before you fly

• Eastbound: Shift bedtime and wake time 1 hour earlier each night for 3 nights. Get bright light immediately upon waking.
• Westbound: Shift bedtime 1 hour later each night. Stay up under bright light; sleep in the next morning.
• Move meals with the schedule, not just sleep. Eating at the new time reinforces the shift through peripheral clocks in the liver and gut.
• Book flights with the shift in mind where you can: an eastbound overnight that lands mid-morning gives you a full day of correctly-timed light, while one that lands at 5 AM does not.
• Use the sleep calculator to find cycle-aligned bedtimes for your new target time.

Two nights of pre-shifting is enough to matter. Three is better. If you cannot pre-shift at all — a common reality with work travel — skip straight to the arrival light plan and accept an extra day of adjustment rather than doing a half-hearted shift in the wrong direction.

On the plane

• Set your watch to destination time the moment you board. Eat and sleep on the new schedule from that point.
• Skip alcohol — it fragments REM and worsens dehydration, both of which extend jet lag.
• Cap caffeine at one cup, more than 8 hours before your target destination bedtime.
• If your destination time is "night" during the flight, use eye mask + earplugs + a 90-minute sleep block (one full cycle).
• If your destination time is "day," stay awake with the window shade up and the reading light on. Sleeping through destination daytime is the most common self-inflicted jet-lag wound.
• Walk the aisle once an hour while awake. Movement raises core temperature slightly and helps hold off sleep pressure at the hours you need to stay up.

The light strategy at your destination

Light is by far the most powerful zeitgeber (clock-setter). Getting it at the wrong time can make jet lag worse. As a simple rule:

• Flew east (e.g. US → Europe): Seek bright outdoor light in the destination morning. Avoid bright light in the early morning of the first 1–2 days if you woke before 5 AM local — this is your body's "biological night" and light there pushes the clock the wrong way.
• Flew west (e.g. Europe → US): Seek bright light in the destination evening. Avoid bright morning light for the first day if you wake unusually early.

In practice, "avoid light" means sunglasses plus a hat outdoors and dim indoor lighting — not sitting in a dark room. And "seek light" means going outside. An overcast morning outdoors still delivers 5,000–10,000 lux; a well-lit office delivers 300–500. There is no indoor substitute short of a dedicated 10,000-lux therapy lamp. Our morning light guide covers the mechanics in more detail.

Melatonin: dose, timing, and what to expect

The Cochrane review found 0.5–5 mg of melatonin taken at destination bedtime for the first 4–5 nights modestly speeds adjustment, especially eastbound across 5+ time zones. Lower doses (0.3–0.5 mg) match natural physiologic levels and are usually enough. Higher doses can cause morning grogginess.

Melatonin is a clock-setter, not a sedative. If you cannot fall asleep, the issue is usually light exposure, not dose. Pair melatonin with a dark, cool room and a calming routine.

Two cautions. Melatonin is regulated as a supplement in the United States, so actual content varies between products and batches — buy from a brand that publishes third-party testing. And check with a clinician first if you take anticoagulants, immunosuppressants, or anti-seizure medication, or if you are pregnant.

A sample 5-day plan: New York → London (5 hours east)

1. Days −3 to −1 (NY): Bedtime 1 hr earlier each night. Bright light at wake.
2. Travel day: Set watch to London time at boarding. Sleep block in last 3–4 hrs of flight. No alcohol.
3. Day 1 (London): 30+ min outdoor light between 8–11 AM. Light walk after lunch. 0.5 mg melatonin at 10 PM. Bed at 11 PM.
4. Days 2–3: Same morning-light pattern. Permit one 20-minute nap before 2 PM if needed.
5. Day 4: Drop melatonin. Maintain consistent wake time.

And the return leg: London → New York (5 hours west)

1. Day −1 (London): Stay up an hour later than usual under bright light. No pre-shift needed beyond that.
2. Travel day: Daytime flight — stay awake. Land mid-afternoon and go outside.
3. Day 1 (NY): Bright evening light until 8 PM. No nap after 2 PM. Bed 10:30–11 PM local even though it feels like 4 AM.
4. Day 2: Expect a 4 AM wake. Stay in bed in the dark; do not check your phone. Read our guide on breaking the middle-of-the-night loop.
5. Day 3: Usually normal. Westbound resolves quickly if you protect the evening.

Westbound is easier, but don't overdo it

For Europe → US, the temptation is to nap immediately on arrival. Resist. A 20-minute nap is fine; a 3-hour nap will trap you in a multi-day cycle of late nights and afternoon crashes. Stay outdoors in the destination afternoon and aim for a bedtime around 10:30 PM local on night 1.

Special cases worth planning for

• Trips under three days: Stay on home time. Book meetings in the overlap hours and treat the trip as a night shift — see our shift work guide.
• Crossing 8+ zones: Full adjustment can take over a week eastbound. Consider a deliberate stopover, or plan the first two days as low-stakes.
• Athletes and performers: Aim to arrive one day per time zone before the event where budget allows; this is standard practice in professional sport for good reason.
• Travelling with children: Children re-entrain faster but tolerate the transition worse. Prioritise their light exposure and hold their meal times firmly; expect two rough evenings.
• Night flights with a short block: If you can only sleep four hours, take it in one continuous block rather than two fragmented ones. Cycle integrity matters more than total minutes on a plane.

What to tell yourself when it's still rough

Even with perfect technique, eastbound trips across 6+ zones often produce one bad night around day 2 — a "circadian whiplash" night when your body is roughly halfway shifted. Expect it. A short walk in evening light, a warm shower, and a 4-7-8 breathing round can shorten the wake. Read our breathing exercises guide.

It also helps to lower the bar for what counts as success. Jet lag recovery is not "sleeping perfectly from night one." It is a series of slightly better nights where you protect the wake time, get outside in the morning, and refuse the 4 PM nap. Do those three things and the clock catches up on its own schedule.

The one-line summary

Pre-shift your schedule, set your watch on boarding, chase light at the destination, use low-dose melatonin at destination bedtime, and accept one rough night around day 2.

Jet Lag FAQ

How long does jet lag actually last?

Without intervention, the circadian clock re-entrains at roughly one time zone per day travelling east and about one and a half zones per day travelling west. A five-zone eastbound trip therefore takes about five days, and the same trip westbound takes about three. Pre-shifting your schedule and timing light exposure correctly typically cuts that in half.

Is eastbound or westbound jet lag worse?

Eastbound is consistently worse. The free-running human clock is slightly longer than 24 hours, so delaying your schedule (flying west) works with your biology while advancing it (flying east) works against it. Phase advances are the hardest shift in chronobiology, which is why eastbound trips need a pre-flight plan rather than an arrival plan.

How much melatonin should I take for jet lag, and when?

The Cochrane review supports 0.5–5 mg taken at destination bedtime for the first four to five nights, with the strongest effect on eastbound flights across five or more zones. Doses of 0.3–0.5 mg match physiological levels and are usually enough; higher doses mainly add morning grogginess. Timing matters far more than dose because melatonin acts as a clock signal, not a sedative.

Should I nap when I land?

A single nap of 20 minutes or less, finished before 2 PM local time, will take the edge off without eroding the sleep pressure you need that night. Anything longer than 45 minutes lets you drop into deep sleep, which produces grogginess on waking and pushes bedtime later — the exact loop that keeps jet lag alive for a week.

Does staying hydrated cure jet lag?

No. Cabin air is dry and dehydration makes you feel worse, so drinking water helps the symptoms you notice on the plane. It does nothing to move your circadian clock. Only correctly timed light, and to a lesser degree melatonin, meal timing, and exercise, actually shift the clock.

Is jet lag worth managing for a two-day trip?

Usually not. For trips of two or three days across four or more zones, most travellers do better staying anchored to home time — scheduling meetings in the overlap window and treating the trip as a night shift — rather than half-shifting and then shifting back. Full adjustment is worth it from about four days on the ground.