Melatonin for Jet Lag: Dose, Timing, and Direction
Melatonin is one of the few supplements with trial evidence for a travel problem. The rules are specific: doses from 0.5 to 5 mg at destination bedtime, more benefit crossing five-plus time zones eastward, and a real risk of backfiring when mistimed.
Key takeaways
- A Cochrane review of ten randomized trials found melatonin near target bedtime cut jet-lag scores on flights crossing five or more time zones, with a number needed to treat of two.
- Doses between 0.5 and 5 mg performed about equally in the review, while doses above 5 mg added nothing — and 2 mg slow-release underperformed the short-lived peak.
- Public-health travel guidance frames eastward trips as phase advances and westward trips as phase delays, with timed light and melatonin pulling in the same direction.
- Taking melatonin when the body already has high overnight levels adds little; the same guidance favors 0.5 to 1 mg over high doses that linger at the wrong clock hour.
- Wrong-time dosing does more than fail: the Cochrane authors found early-day melatonin caused daytime sleepiness and slowed adaptation to local time.
What This Guide Covers
Melatonin is one of the few supplements with trial evidence for a travel problem. The rules are specific: doses from 0.5 to 5 mg at destination bedtime, more benefit crossing five-plus time zones eastward, and a real risk of backfiring when mistimed. This guide walks you through what matters most, why it happens, and the practical steps with the best support behind them.
First, the foundation: a Cochrane review of ten randomized trials found melatonin near target bedtime cut jet-lag scores on flights crossing five or more time zones, with a number needed to treat of two.
Next, the details: doses between 0.5 and 5 mg performed about equally in the review, while doses above 5 mg added nothing — and 2 mg slow-release underperformed the short-lived peak.
Then, the practical side: public-health travel guidance frames eastward trips as phase advances and westward trips as phase delays, with timed light and melatonin pulling in the same direction.
Another angle worth knowing: taking melatonin when the body already has high overnight levels adds little; the same guidance favors 0.5 to 1 mg over high doses that linger at the wrong clock hour.
Finally, the big picture: wrong-time dosing does more than fail: the Cochrane authors found early-day melatonin caused daytime sleepiness and slowed adaptation to local time.
Frequently Asked Questions
What exactly is melatonin for jet lag?
Melatonin is one of the few supplements with trial evidence for a travel problem. The rules are specific: doses from 0.5 to 5 mg at destination bedtime, more benefit crossing five-plus time zones eastward, and a real risk of backfiring when mistimed.
How long until I see improvement?
Most of the strategies in this guide start showing effect within one to two weeks of consistent practice. Supplement- and device-based approaches vary more, so track your nights in a simple sleep diary and judge by weekly trends rather than single nights.
When should I see a doctor?
If the problem lasts more than a few weeks, disrupts your daytime functioning, or comes with warning signs such as breathing pauses, gasping during sleep, chest discomfort, or severe daytime sleepiness, it is time to consult a qualified healthcare professional rather than self-treating.
References
- Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews. 2002;(2):CD001520.
- Centers for Disease Control and Prevention. Jet Lag Disorder (Yellow Book).
- National Center for Complementary and Integrative Health. Melatonin: What You Need To Know.