Melatonin is a hormone found naturally in the body. Melatonin used as medicine is usually made synthetically in a laboratory. It is most commonly available in pill form, but melatonin is also available in forms that can be placed in the cheek or under the tongue. This allows the melatonin to be absorbed directly into the body.

Melatonin is generally safe for short-term use. Unlike with many sleep medications, with melatonin you are unlikely to become dependent, have a diminished response after repeated use (habituation), or experience a hangover effect.