0.5 mg of melatonin helped jet-lag sleep almost as much as 5 mg
In one trial of 234 travellers flying east, 0.5 mg at bedtime did nearly as well as 5 mg on sleep and tiredness; a 2 mg slow-release form did less.
What the study found
Half a milligram worked almost as well as 5 mg after eastward flights
In 234 travellers, 5 mg of fast-release melatonin at bedtime improved sleep and daytime tiredness, and 0.5 mg did almost as well, falling short only on getting to sleep and sleep quality. A 2 mg slow-release form did less than either. A tenth of the dose did most of the work.
The caveat · Overall jet-lag score didn't differ
This rests on one trial, and its benefit showed in sleep and tiredness ratings rather than an overall jet lag score. About a quarter of those enrolled were dropped for missing doses or leaving. In the largest jet lag trial, neither 0.5 mg nor 5 mg beat placebo.