Adjust your biological clock. During the 2-3 days prior to a long trip, get adequate sleep. You can make minor changes to your sleep schedule. For example, if you are traveling west, delay your bed time and wake time progressively by 20- to 30-minute intervals. If you are traveling east, advance your wake time by 10 to 15 minutes a day for a few days and try to advance your bed time. Decreasing light exposure at bedtime and increasing light exposure at wake time can help you make these adjustments. When you arrive at your destination, spend a lot of time outdoors so your body gets the light cues it needs to adjust to the new time zone. Take a couple of short 10-15 minute catnaps if you feel tired, but do not take long naps during the day.
Avoid alcohol and caffeine. Although it may be tempting to drink alcohol to relieve the stress of travel and make it easier to fall asleep, you're more likely to sleep lighter and wake up in the middle of the night when the effects of the alcohol wear off. Caffeine can help keep you awake longer, but caffeine also can make it harder for you to fall asleep if its effects haven't worn off by the time you are ready to go to bed. Therefore, it's best to use caffeine only during the morning and not during the afternoon.
What about melatonin? Your body produces this hormone that may cause some drowsiness and cues the brain and body that it is time to fall asleep. Melatonin builds up in your body during the early evening and into the first 2 hours of your sleep period, and then its release stops in the middle of the night.
Melatonin is available as an over-the-counter supplement. Because melatonin is considered safe when used over a period of days or weeks and seems to help people feel sleepy, it has been suggested as a treatment for jet lag. But melatonin's effectiveness is controversial, and its safety when used over a prolonged period is unclear. Some studies find that taking melatonin supplements before bedtime for several days after arrival in a new time zone can make it easier to fall asleep at the proper time. Other studies find that melatonin does not help relieve jet lag.
From NHLBI.NIH.gov
