Wellness · Sleep & rest
Jet lag — a practical playbook.
Light timing, melatonin, and simple pre-flight prep can shorten jet lag from a week to two nights. Here is the evidence-based playbook.
Why trust this guide
- 01
Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
- 02
Sourced from evidence
Every claim is checked against the AASM, CDC or a peer-reviewed source you can see at the end.
- 03
Practical, not preachy
A real playbook you can start two days before your flight — no gimmicks, no supplement upsells.
Key facts
Jet lag at a glance.
The essentials, in plain English — what it is, why direction matters, the levers that work, and when to prep.
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What it is
A mismatch between your internal body clock and the local time at your destination.
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Direction matters
Eastward travel is harder than westward — advancing the clock is tougher than delaying it.
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Recovery rule of thumb
Roughly one day of adjustment per time zone crossed if you do nothing.
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The three levers
Light exposure, low-dose melatonin, and meal timing — used together, not in isolation.
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When to prep
Start shifting bedtime 2-3 days before you fly for the biggest gain.
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When it is bigger
Shift-workers and frequent long-haul flyers can develop persistent circadian disruption.
Why this guide matters
A week off, or two nights?
Most jet-lag advice is folklore. The three points below shape everything else on this page.
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Direction is destiny
Eastward flights advance your clock and take roughly 50% longer to recover from.
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Light is the master signal
Timed sunlight moves the clock faster than any pill or supplement.
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Prep beats reaction
Two or three days of pre-flight sleep shift outperform anything you do in the air.
The playbook
The steps that actually shorten recovery.
A pragmatic order — pre-flight prep first, arrival tactics next, in-flight discipline throughout.
Phase 1 · Prep
Direction, sleep shift, light plan
Phase 2 · In-flight
Melatonin plan, no alcohol
Phase 3 · Arrival
Move, hydrate, local meal times
- 01
Prep
Identify direction of travel
Eastward flights advance your clock and are consistently harder to adapt to than westward flights.
- 02
Prep
Shift bedtime 1 hour per day
For 2-3 days before travel, move sleep and wake times toward the destination — earlier for east, later for west.
- 03
Prep
Use light strategically
On arrival: bright morning light for eastward trips, bright evening light for westward trips.
- 04
In-flight
Low-dose melatonin
0.5-3 mg at destination bedtime for 3-5 nights — timing matters more than dose.
- 05
In-flight
Avoid alcohol in flight
Alcohol worsens dehydration and fragments the little sleep you might get in the air.
- 06
Arrival
Move and hydrate
Walk the cabin every couple of hours and drink water steadily — small, boring, effective.
- 07
Arrival
Adopt local meal times
Eat on the destination’s schedule from arrival — meal timing is a powerful zeitgeber alongside light.
Typical recovery with the playbook: 1-2 nights instead of a day per time zone.
Signs it affects you
How jet lag actually shows up.
A quick self-check. A few of these on day one is normal; a pattern beyond a week is a nudge to act.
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Difficulty sleeping at local bedtime
Lying awake for hours despite feeling tired earlier in the day.
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Early or late waking
Popping awake at 3am, or sleeping through the morning you meant to explore.
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Digestive upset
Bloating, constipation or altered appetite as your gut clock lags behind.
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Low mood or irritability
Short fuse, flat affect — sleep loss and circadian mismatch both drive it.
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Poor concentration
Slower thinking, missed details, and that mid-afternoon fog.
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Athletic performance drop
Reaction time, strength and endurance all dip until the clock catches up.
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Appetite disruption
Hungry at odd hours, uninterested at meal times — a classic circadian sign.
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Red flag
Symptoms persisting beyond 10 days — investigate other causes such as depression or a sleep disorder.
How to do it
Eight tactics, stacked over 5 days.
Start 2-3 days before travel and keep going through the first 3-5 nights at destination. You do not need all eight — pick what fits.
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Pre-flight sleep shift
Move bedtime 1 hour per day for 2-3 days before travel toward the destination’s clock.
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Strategic light exposure
Morning light on arrival for eastward trips; evening light for westward trips. Sunlight beats lamps.
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Melatonin (short-term, low-dose)
0.5-3 mg at destination bedtime for 3-5 nights. Higher doses do not work better.
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In-flight hydration
Steady water intake through the flight — cabin air is dry and dehydration worsens fatigue.
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Avoid alcohol in flight
It fragments sleep, worsens dehydration and delays circadian adjustment.
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Adopt local meal times
Eat on the destination clock from arrival — meal timing anchors peripheral body clocks.
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Short strategic naps
20-30 minutes early afternoon local time if you must nap — anything longer erodes night sleep.
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Zeitgeber-based apps
Apps like Timeshifter build personalised light, sleep and caffeine schedules from your itinerary.
What this guide is based on
The sources behind every claim on this page.
Specialist society guidance and peer-reviewed sleep-medicine literature, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
If symptoms persist beyond 10 days, or you develop palpitations, chest pain or leg swelling after a long flight, please see a doctor.
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American Academy of Sleep Medicine. Position on jet lag disorder.
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Journal of Clinical Sleep Medicine. Circadian rhythm sleep-wake disorders.
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CDC. Travel health — jet lag.
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The Sleep Charity. Jet lag and travel.
Red flags
When it is not just jet lag.
These signs suggest a different underlying problem — the playbook alone will not fix them. Escalate.
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Symptoms beyond 10 days
True jet lag resolves within days per time zone. Persisting fatigue warrants another look.
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New arrhythmia after a long flight
Palpitations or an irregular pulse — atrial fibrillation is more common after long-haul travel.
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Chest pain or leg swelling
Rule out deep-vein thrombosis or pulmonary embolism — seek same-day assessment.
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Falling asleep while driving
A legal and safety emergency after return — do not drive, seek same-day assessment.
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Persistent insomnia
Poor sleep continuing weeks after travel is not jet lag — see our Insomnia guide.
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Mood collapse
New depression or anxiety after travel — jet lag can unmask underlying mood issues.
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Restless legs post-travel
Creeping urge to move the legs at rest — a different diagnosis, worth reviewing.
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Frequent-flyer chronic issues
Ongoing sleep, mood or cognitive problems in regular long-haul travellers — see a sleep specialist.
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Melatonin needing to escalate
Needing higher and higher doses to sleep — a signal to reassess rather than push the dose.
Making it stick
A repeatable routine, not a perfect one.
Four principles to keep the playbook usable trip after trip.
A quiet reminder
Prep two days early, and the flight takes care of itself.
The heavy lifting happens before you board — the in-flight and arrival tactics are just there to hold the gains.
- 01 Preparation
Shift before you fly
Two or three days of gradual bedtime shift beats any in-flight trick.
- 02 Light
Light is the master signal
Get outside on arrival — natural light adjusts the clock faster than any supplement.
- 03 Restraint
Low dose, short course
Melatonin works best at 0.5-3 mg for a handful of nights, not indefinitely.
- 04 Realism
One day per time zone
Even with a good playbook, expect a couple of nights of imperfect sleep.
Frequently asked
Everything we get asked about jet lag.
Quick answers on direction, melatonin, apps, caffeine, recovery time and when to see a doctor.
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Why is eastward travel worse than westward?
Your body clock naturally runs slightly longer than 24 hours, so delaying it (going west) is easier than advancing it (going east). Most people find eastward flights take roughly 50% longer to recover from.
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How much melatonin should I take?
0.5-3 mg at destination bedtime for 3-5 nights is the evidence-based range. Higher doses do not work better and can cause grogginess. Timing matters more than dose.
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Do I need a jet-lag app?
Apps like Timeshifter build a personalised light, sleep and caffeine schedule from your itinerary. Useful for multi-leg trips or frequent flyers; not essential for a single hop.
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Does caffeine help?
Yes, in the destination morning — it helps you stay alert during local daytime. Avoid it within 6-8 hours of local bedtime or you will make the mismatch worse.
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How long will jet lag last?
Roughly one day of adjustment per time zone crossed if you do nothing. A good pre-flight shift plus light and melatonin can cut that to 1-2 nights for most trips.
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When should I see a doctor?
If sleep, mood or cognitive symptoms persist beyond 10 days, if you develop palpitations, chest pain or leg swelling after a long flight, or if you are a frequent long-haul traveller with ongoing issues.
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