If something hinders this process, like changing time zones or developing a sleep rhythm disorder, small amounts of synthetic melatonin, sold over-the-counter, may help you readjust to a normal sleep schedule.
Melatonin won't work for every case of insomnia or sleeping problems, though. "Your body has to be ready for sleep for melatonin to work," says David Rapoport, MD, medical director of the New York University Sleep Disorders Clinic. "So for those people who have insomnia because they just don't get sleepy—we call this hyperarousal—melatonin won't do them much good."
More nonprescription options
The following is from our A-Z Health Library:
What is melatonin?
Melatonin is a hormone produced in the pineal gland (see an illustration here), a small gland in the brain, that helps regulate sleep and wake cycles. Very small amounts of melatonin are found in foods such as meats, grains, fruits, and vegetables. It is also available as a dietary supplement, though it has no known nutritional value.
What does natural melatonin do in the body?
Your body has its own internal clock that helps regulate your natural cycle of sleeping and waking hours (or circadian rhythm) in part by controlling the production of melatonin. Normally, melatonin levels begin to rise in the mid- to late evening, remain high for most of the night, and then decline in the early morning hours.
Natural melatonin production is partly affected by light. During the shorter days of the winter months, melatonin production may start earlier or, more often, later. This change can lead to symptoms of seasonal affective disorder (SAD), or winter depression.
Natural melatonin levels decline gradually with age. Some older adults produce very small amounts of melatonin or none at all.
Melatonin is a hormone produced in the pineal gland (see an illustration here), a small gland in the brain, that helps regulate sleep and wake cycles. Very small amounts of melatonin are found in foods such as meats, grains, fruits, and vegetables. It is also available as a dietary supplement, though it has no known nutritional value.
What does natural melatonin do in the body?
Your body has its own internal clock that helps regulate your natural cycle of sleeping and waking hours (or circadian rhythm) in part by controlling the production of melatonin. Normally, melatonin levels begin to rise in the mid- to late evening, remain high for most of the night, and then decline in the early morning hours.
Natural melatonin production is partly affected by light. During the shorter days of the winter months, melatonin production may start earlier or, more often, later. This change can lead to symptoms of seasonal affective disorder (SAD), or winter depression.
Natural melatonin levels decline gradually with age. Some older adults produce very small amounts of melatonin or none at all.
Last Updated: July 28, 2008 
