Does melatonin help with jet lag?

Yes. Low-dose melatonin (0.5–3mg) taken 30 minutes before your target bedtime at the destination is supported by multiple meta-analyses as effective for reducing jet lag severity. For eastward travel, take it in the evening at the destination. For westward travel, timing is less critical but evening doses still help anchor the new schedule.

How can I prevent jet lag before a flight?

The most effective pre-travel strategy is to gradually shift your sleep schedule 2–3 days before departure in the direction of your destination. Moving bedtime 30–60 minutes earlier each day (for eastward travel) or later (for westward travel) pre-adapts your circadian clock and reduces adjustment time at the destination.

What is the best thing to do on the plane to avoid jet lag?

Set your watch to destination time immediately upon boarding. Sleep on the plane only if it is nighttime at your destination. Use an eye mask and earplugs to facilitate sleep. Stay well-hydrated and avoid alcohol and heavy meals, both of which fragment sleep and worsen circadian disruption. Avoid caffeine within 6 hours of your intended destination bedtime.

Based on Circadian Science · East vs West · Recovery Timeline

Jet Lag Calculator —
How Long to Recover & Reset Your Body Clock

Q: How long does jet lag last?

Jet lag typically lasts 1 day per time zone crossed when traveling east, and slightly less when traveling west. A 5-hour eastward shift usually means 5–7 days to fully adjust, while the same westward shift takes 4–5 days. The severity depends on the number of time zones crossed, direction of travel, your age, and individual chronotype.

Q: Is jet lag worse going east or west?

Jet lag is consistently worse when traveling east. Flying east requires your circadian clock to advance (go to bed and wake earlier), which is harder for most people because the human body naturally runs on a slightly longer than 24-hour cycle — making it easier to delay (go later) than to advance. Eastward travel causes a phase advance, westward travel causes a phase delay.

Cross multiple time zones and your internal clock falls out of sync with local time. Enter your travel details below to find out how long recovery takes and get personalized evidence-based strategies to reset faster.

Direction of Travel

Time Zone Difference

hrs

Or Use Slider

1 hr7 hrs14 hrs

Example: NYC → London = 5 hrs · NYC → Tokyo = 14 hrs

~1 day/hr

recovery time eastward

25%

harder going east vs west

3–5 days

avg. recovery for 5-hr shift

How long does jet lag last?

Jet lag typically lasts approximately 1 day per time zone crossed when flying east, and slightly less when flying west. A transatlantic flight from New York to London (5 time zones east) usually takes 5–7 days to fully adjust. The same flight in reverse takes 4–5 days.

Severity depends on the number of time zones crossed, direction (east is harder), your age (older adults adjust more slowly), your chronotype, and whether you use jet lag countermeasures like timed light exposure and melatonin.

Symptoms — fatigue, difficulty sleeping at the local time, reduced concentration, digestive disruption — occur because your circadian clock is anchored to your home time zone while local cues (light, temperature, meal times) push toward the new zone. Recovery happens as these signals gradually realign your clock.

Quick Reference

Jet Lag Recovery by Time Zone Difference

Estimated recovery days using the 1-day-per-hour rule for eastward travel. Westward travel typically requires fewer days due to phase delay being easier for the human clock.

Time Zone Shift	Example Routes	Flying East (days)	Flying West (days)
1 hour	London → Paris	2 days	23 days
2 hours	London → Cairo	3 days	22 days
3 hours	London → Moscow	5 days	21 days
4 hours	London → Dubai	6 days	20 days
5 hours	NYC → London	8 days	19 days
6 hours	LA → London	9 days	18 days
7 hours	NYC → Berlin + 1	11 days	17 days
8 hours	NYC → Dubai	12 days	16 days
9 hours	NYC → India	14 days	15 days
10 hours	NYC → Bangkok	15 days	14 days
11 hours	NYC → Tokyo	17 days	13 days
12 hours	LA → Tokyo	18 days	12 days
13 hours	LA → Sydney	20 days	13 days
14 hours	NYC → Tokyo (+3)	21 days	14 days

Individual variation is significant. Older adults, poor sleepers, and those without countermeasures may take longer.

Circadian Science

Why Traveling East Is Harder Than West

Flying East — Phase Advance

When you fly east, local time is ahead of your body clock. If your body thinks it is 10 PM, local clocks say 3 AM. You need to go to sleep before your body is ready and wake before your body clock expects morning.

This is called a phase advance — your clock needs to move earlier. The human circadian clock naturally runs at slightly longer than 24 hours (approximately 24.2 hours), making it biologically easier to stay up later (delay) than to go to sleep earlier (advance).

Symptoms: insomnia at local night, extreme morning fatigue
Key fix: seek bright morning light at destination
Avoid: evening light at destination (it delays further)
Melatonin: take in early evening at destination

Flying West — Phase Delay

When you fly west, local time is behind your body clock. Your body wants to sleep when local time is still evening. You feel sleepy at dinner time but cannot sleep in the next morning because your body clock wakes you early.

This is a phase delay — your clock needs to move later. Since the human clock naturally tends later than 24 hours, this aligns with our biology. Recovery is typically 20–30% faster than equivalent eastward travel.

Symptoms: early-morning waking, daytime sleepiness at dinner
Key fix: seek evening light at destination
Avoid: morning light (it advances your clock further)
Melatonin: optional — less critical than for eastward travel

Evidence-Based Strategies

8 Tips to Beat Jet Lag Faster

Pre-adapt your schedule

Starting 3 days before departure, shift your sleep time 30–60 minutes in the direction of your destination each day. This reduces the adjustment needed on arrival.

Use timed light exposure

Light is the strongest zeitgeber (time cue) for the circadian clock. Eastward travelers: seek bright morning light at the destination. Westward travelers: seek evening light and avoid morning light for the first few days.

Take low-dose melatonin

Take 0.5–3mg melatonin 30 minutes before your target bedtime at the destination. Lower doses (0.5–1mg) are as effective as higher doses with fewer side effects. Supported by Cochrane review evidence.

Sync meal times immediately

Eating at local meal times sends strong circadian signals to peripheral clocks in the digestive system. Switch to destination meal times immediately on arrival — do not eat by home-time hunger cues.

Stay hydrated on the plane

Aircraft cabin humidity is 10–20%, far below the 30–65% comfortable range. Dehydration worsens fatigue, cognitive impairment, and sleep quality — all of which amplify jet lag symptoms.

Avoid alcohol during travel

Alcohol disrupts sleep architecture (particularly REM sleep), dehydrates you, and suppresses melatonin production. A single inflight drink can worsen jet lag severity by 1–2 days.

Exercise at the right time

Light-to-moderate exercise at the destination during morning hours helps advance your clock for eastward travel. Afternoon exercise helps delay it for westward travel. Avoid intense exercise within 3 hours of bedtime at the destination.

Use short strategic naps

If severely sleep-deprived on arrival, a 20-minute nap before 3 PM local time can restore alertness without disrupting nighttime sleep. Avoid long naps (>30 minutes) which can anchor your clock to the wrong time.

Supplement Guide

Melatonin Timing for Jet Lag

Melatonin is most effective when taken at the correct local time — not at home-time bedtime. Here is how to use it for each travel direction.

Flying East

Take 0.5–3mg at destination bedtime (e.g., 10 PM local)
Continue for 3–5 nights until adjusted
Do not take at home-time bedtime (wrong signal)
Combine with morning bright light for best effect

Flying West

Melatonin is optional but helpful for initial nights
Take at destination bedtime if struggling to fall asleep
Evening light exposure is the primary strategy
Phase delay makes westward adjustment naturally easier

Melatonin is generally considered safe for short-term use. Consult a healthcare provider before use if pregnant, nursing, or on blood-thinning medications.

Common Questions

Jet Lag Calculator FAQ

How long does jet lag last?

Jet lag typically lasts approximately 1 day per time zone crossed when traveling east. Westward travel is roughly 20–30% faster to recover from. So a 5-hour eastward shift (e.g., New York to London) takes about 5–7 days for full adjustment, while the same westward leg takes 4–5 days. Using light therapy and melatonin can cut recovery time by 1–3 days.

Is jet lag worse going east or west?

Eastward travel is consistently harder. Flying east requires your circadian clock to advance — going to bed and waking earlier than your body wants. Because the human circadian period is naturally slightly longer than 24 hours (~24.2 hours), it is biologically easier to delay (stay up later, as in westward travel) than to advance (go to sleep earlier). Most people find east-vs-west jet lag noticeably more severe even for equal time zone shifts.

Does melatonin actually work for jet lag?

Yes — melatonin is one of the best-evidenced interventions for jet lag. A Cochrane systematic review found melatonin taken at the correct time (destination bedtime) significantly reduces jet lag severity across multiple measures. Doses as low as 0.5mg are effective. Higher doses (5–10mg) are common in supplements but do not outperform lower doses and may cause morning grogginess.

How do I avoid jet lag before a long-haul flight?

Pre-adapt your schedule by shifting bedtime and wake time 30–60 minutes in the direction of your destination for 2–3 days before departure. Eastward travelers should go to bed and wake earlier; westward travelers should go to bed and wake later. Also get a good night of sleep before travel — departing already sleep-deprived worsens every jet lag symptom.

What should I do on the plane to minimize jet lag?

Set your watch to destination time immediately. Sleep on the plane only if it is nighttime at the destination. Use a sleep mask and earplugs. Drink plenty of water. Avoid alcohol and excess caffeine. Move around every 1–2 hours for circulation. Avoid heavy meals that stress the digestive system and worsen circadian disruption.

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