Melatonin is used for numerous conditions but is showing the most promise in short-term regulation of sleep patterns, including jet lag.
Jet lag: (eastbound travel) - Take a preflight early evening treatment of melatonin followed by treatment at bedtime for 4 days after arrival. Westbound travel- Take melatonin for 4 days at bedtime when in the new time zone. Difficulty falling asleep: Take 5 mg of melatonin 3 to 4 hours before an imposed sleep period over a 4-week period. Difficulty maintaining sleep: Take a high dose, repeated low doses, or a controlled-release formulation. Children (6 months to 14 years of age with sleep disorders): 2 to 5 mg melatonin has been used.