Does melatonin have a meaningful role as a sleep aid for jet lag recovery?

BACKGROUND Melatonin has long been used as an over-thecounter aid to assist with hastening sleep onset and treating symptoms of jet lag, with jet lag being the most common application. The effects of jet lag are greater based on an increase in the number of time zones travelled and when experiencing eastbound travel. Jet lag may have varying effects on an individual, and is associated with cognitive and physiological deficits. Insomnia and constant sleepiness may also occur during the day. Other negative effects may include reduced attention, altered mood states, diminished memory processing, and altered executive functioning. Melatonin has numerous commercially available preparations, and in most countries is not considered a regulated substance. Despite its widespread use as a sleep aid, and its promotion as such by celebrity entertainers and media-based physicians alike, it remains unclear whether or not there is sufficient evidence to support the recommendation of this substance as a sleep aid.