How long does jet lag last?

Rule of thumb: one day of recovery per time zone crossed for eastbound travel, half as much for westbound. A 6 hour eastbound trip from NYC to Europe takes most people 4 to 6 days to fully clear.

Is eastbound or westbound jet lag worse?

Eastbound, for most people. Going east shortens your day, which fights the natural tendency of the circadian rhythm to drift later. Going west extends your day, which is easier for the body.

Do melatonin supplements work for jet lag?

Yes, with caveats. Low-dose melatonin (0.3 to 0.5mg) taken at the new local bedtime for 3 to 5 days is the best-evidenced supplement intervention. Higher doses are not better and often cause grogginess.

Jet lag recovery: the plan that actually works

How to reset your body clock after a long flight in as little as three days, using light, sleep timing and a strategically designed alarm.

Jet lag is a circadian alignment problem. Your internal clock is running on one time zone while you are trying to function on another. The official symptoms (fatigue, poor sleep, GI upset, mood dips) are all downstream of that mismatch. The cure is realignment, as fast and cleanly as possible.

The fundamentals

The two strongest tools for realigning the circadian rhythm are:

Light exposure (and its absence)
Sleep timing

Everything else (melatonin, diet timing, exercise) adjusts around those two.

Before you fly

Eastbound trip (US to Europe, Asia, etc): start shifting bedtime earlier by 30 to 60 minutes per night for 3 nights before departure. Get bright morning light.

Westbound trip (Europe to US, Asia to Europe): shift bedtime later by 60 minutes for 2 nights before. Get evening light.

Most people skip this step. It saves roughly 1 to 2 days of recovery on arrival.

On the plane

Set your watch and phone to the destination time zone the moment you board
Sleep on the plane only if it is night at your destination
If it is daytime at your destination, stay awake (eye mask off, read, watch TV)
Hydrate. Cabin air dehydrates you and dehydration worsens the downstream symptoms
Limit alcohol. One drink is fine. More and the jet lag compounds.

On arrival: the 72 hour plan

Day 0 (arrival day)

Eastbound: you arrive in the local morning, tired. Resist sleeping during the day. Take a maximum 20 minute nap if you are falling over, otherwise stay awake. Bright light exposure the first hour you are up. Light meal at local meal times. Bed at local bedtime, not earlier.

Westbound: you arrive in the local afternoon, tired. Walk outside, get sun, have a light meal. You can sleep at local bedtime. This side is easier.

Day 1

Alarm at local target wake time, regardless of how you feel
Bright light in the first 30 minutes of being awake
Outside within 2 hours of waking
Local meal times
Bed within 30 minutes of local target bedtime, even if you do not feel sleepy

Day 2

Same pattern as day 1
Most people feel 70 percent recovered by end of day 2 westbound, day 3 eastbound

Day 3

Should feel normalized for small time zone shifts (up to 5 hours)
Larger shifts (8 plus hours) typically need 4 to 7 days

The critical alarm design

On arrival days, the alarm is doing more work than at home because your body is fighting you. A bad alarm setup turns 2 days of recovery into 5.

Set the alarm for local target wake time, every single morning. No sleep-in days. The strict schedule is what pulls the circadian rhythm along.
Use a song you associate with energy. Default iOS tones fail here because your body is already resisting. A track with emotional or energetic weight gets through faster.
Use a 30 to 60 second gradual fade. You want to lift out of sleep, not be yanked.
Backup alarm 8 minutes later, because the risk of oversleeping is genuinely high during recovery.

Setup guides: Set Spotify or Apple Music. Multiple alarms: set multiple alarms on iPhone. Gradual fade: gradual wake-up alarms.

Melatonin protocol

If you want to use melatonin for jet lag:

Dose: 0.3 to 0.5mg (not 5mg). Higher doses do not help and cause morning grogginess.
Timing: 30 minutes before local target bedtime.
Duration: 3 to 5 days, then stop.
Eastbound trips benefit more than westbound.

Consult a doctor if you take other medications. Melatonin interacts with some antidepressants and blood thinners.

Common mistakes

Sleeping from 5pm to 7pm on arrival. Feels amazing in the moment, ruins the night. Stay up until local bedtime.

Napping for 90 minutes on day 1. You enter REM, wake up more disoriented. Power nap only: power nap alarm setup.

Over-caffeinating. Coffee becomes seductive during jet lag. Limit to morning only. Afternoon coffee delays recovery by 1 to 2 days.

Skipping sunlight. The single biggest mistake. Artificial indoor light (200 to 500 lux) is not strong enough to shift the circadian rhythm. Sunlight (10,000 plus lux) is.

Pretending you are fine. Cognitive performance during peak jet lag is genuinely impaired. Avoid critical decisions, heavy meetings and driving in unfamiliar places on days 1 and 2.

Short trip strategy

If you are flying for less than 3 days (business trip, long weekend), do not bother adapting. Stay on your home time zone as much as possible. Fighting to adapt for 48 hours and then fighting to adapt back rarely works.

Chronic jet lag

Regular international flights within a 30 day window mean your circadian rhythm never fully stabilizes. This is genuinely bad for long-term health. If this is your job, work with a sleep specialist. Mitigation strategies exist (strict light timing, timed exercise, melatonin protocols) but require professional guidance.

The honest expectation

Jet lag gets better with age-specific strategy and worse with age. People in their 50s and 60s need roughly 1.5 times as long to recover as people in their 20s. Build in slack accordingly.

Most short-haul jet lag (up to 3 time zones) clears in 2 days with a decent plan. Long-haul can take a full week. Respect the recovery window instead of scheduling a presentation on day 1.