Abstract: The present invention relates to low-dose formulations of melatonin, and methods of use thereof, which provide a sustained release of melatonin so as to rapidly increase plasma levels of melatonin, maintain a relatively high level (which mimics the endogenous level of a young subject) for approximately 5-6 hours, and then decrease so as to achieve low levels by early morning (rapid washout), thereby avoiding a “hangover effect”. The sustained release formulations of the invention may be used to treat a variety of sleep-related disorders, including, but not limited to, delayed onset and maintenance forms of insomnia.