Use the power of light
Bright light helps keep our internal clock in sync with the outside world, traveling to special cells in the retina and signaling the part of the brain that sets the body’s master schedule. So, for longer trips, seek out or avoid bright light at specific times, says Dr. Olson. Starting a few days before your trip, gradually shift the light and dark hours from your origin to your destination, using dark glasses, sunlight or other light sources.
In the early days of your trip, knowing the best times to have light can be confusing. Let’s say you’re taking an overnight flight from New York to London, arriving at 7 am Your brain may still feel like 2 am, and having bright light right away can confuse your internal clock. In this case, you may want to wear dark glasses for a few hours, then go out in the sun when it’s closer to your waking time at home, extending your London day.
On long trips to Asia — when day and night are reversed — it’s often easier to switch your cycle back, says Mickey Beyer-Clausen, chief executive of Timeshifter, which makes a jet lag app of the same name. For example, when flying non-stop from New York to Tokyo, which is 13 hours earlier, think of it as 11 hours behind (jet lag does not take the international date line into account). That means if you end up at, say, 2 pm in Japan — 1 am in New York — you have to contend with the fact that your New York brain is breathing to sleep. This means looking for bright light throughout the afternoon, especially at night, until bedtime in Japan. You can also get an early start on adjusting to afternoon time if you go to bed and find light later than usual during the two nights before you leave New York.
Online tools like Jet Lag Rooster and Timeshifter helps create a customized schedule based on variables such as time zone differences, departure and arrival times, and other factors.
Consider melatonin
If you’re having trouble falling asleep earlier in anticipation of the trip east, Dr. Kapur to take one milligram of over-the-counter melatonin about four hours before bed, up to three days before the trip. (Melatonin is a substance produced naturally in the body at nightfall, signaling that it’s time to sleep.) This small dose is best for reducing jet lag, says Dr. Olson, because studies show larger doses don’t necessarily work better and are less likely to produce side effects. Travelers should be aware that as a dietary supplement, melatonin is not regulated by the Food and Drug Administration.