Nine of the ten trials found that melatonin, taken close to the target bedtime at the destination (10pm to midnight), decreased jet-lag from flights crossing five or more time zones. Daily doses of melatonin between 0.5 and 5mg are similarly effective, except that people fall asleep faster and sleep better after 5mg than 0.5mg. Doses above 5mg appear to be no more effective. The relative ineffectiveness of 2mg slow-release melatonin suggests that a short-lived higher peak concentration of melatonin works better. Based on the review, the number needed to treat (NNT) is 2. The benefit is likely to be greater the more time zones are crossed, and less for westward flights. The timing of the melatonin dose is important: if it is taken at the wrong time, early in the day, it is liable to cause sleepiness and delay adaptation to local time.
§ See the light! Light exposure is one of the key determinants of your body’s circadian rhythm. If you’re traveling east, get bright sun exposure in the morning; if you’re traveling west, light later in the day will facilitate your adjustment. If you’re stuck inside, use a light box or another source of bright artificial light.
§ Maximize sleep during the first few nights. Resist napping and make your new environment conducive to good sleep. Use a fan to create white noise to drown out annoying sounds, and keep the thermostat set at 65° F.
§ Eat meals at appropriate local times. Even if you aren’t hungry, scheduling meals by the local clock will help you adjust. Avoid the urge to eat at off times. To eat optimally for jet lag, eat meals with high-protein foods to stay awake and include more carbohydrates when you’re preparing for sleep.
§ Exercise. Don’t let feeling tired and sore from travel keep you from physical activity
Jet lag : Eastbound travel : A preflight, early evening treatment of melatonin should be followed by treatment at bedtime for 4 days after arrival. Westbound travel : Melatonin for 4 days at bedtime when in the new time zone.Sleep disorders : Difficulty falling asleep : Melatonin 5 mg 3 to 4 hours before an imposed sleep period over 4 weeks.