Light and melatonin treatment for jet lag

Jet lag emerges after rapid air travel across several time zones, because the circadian system cannot adjust instantaneously to the new time zone. Jet lag symptoms include difficulty initiating or maintaining sleep, excessive daytime sleepiness, decrements in performance, and gastrointestinal distress. When the circadian timing system is aligned with the new time zone, these symptoms disappear. We review how to shift the circadian clock using appropriately timed bright light, sleep/dark, and exogenous melatonin to reduce or prevent jet lag. We present specific examples of when to use melatonin, dark (sleep) and bright light for flights seven time zones east.