Melatonin is a hormone made by the pineal gland, a small gland in the brain. Melatonin helps control your sleep and wake cycles. Very small amounts of it are found in foods such as meats, grains, fruits, and vegetables. You can also buy it as a supplement.
Your body has its own internal clock that controls your natural cycle of sleeping and waking hours. In part, your body clock controls how much melatonin your body makes. Normally, melatonin levels begin to rise in the mid- to late evening, remain high for most of the night, and then drop in the early morning hours.
Light affects how much melatonin your body produces. During the shorter days of the winter months, your body may produce melatonin either earlier or later in the day than usual. This change can lead to symptoms of seasonal affective disorder (SAD), or winter depression.
Natural melatonin levels slowly drop with age. Some older adults make very small amounts of it or none at all.
It may be that melatonin, when taken as a supplement, can stop or slow the spread of cancer, make the immune system stronger, or slow down the aging process. But these areas need more research.
Melatonin is also being studied to see if it can be used to treat sleep problems in people who are blind.1 Since these people cannot see light, they may have sleep problems such as sleeping during the day and being awake at night.
In most cases, melatonin supplements are safe in low doses for short-term and long-term use. But be sure to talk with your doctor about taking them.
Children and pregnant or nursing women should not take melatonin without talking to a doctor first.
Melatonin does have side effects. But they will go away when you stop taking the supplement. Side effects may include:
If melatonin makes you feel drowsy, do not drive or operate machinery when you are taking it.
During health exams, tell your doctor if you are taking melatonin. And tell your doctor if you are having trouble sleeping (insomnia), because it may be related to a medical problem.
In adults, melatonin is taken in doses from 0.2 to 20.0 mg, based on the reason for its use. The right dose varies widely from one person to another. Talk to your doctor to learn the right dosage and to find out if melatonin is right for you.
You can buy melatonin supplements without a prescription at health food stores, drugstores, and online. Melatonin should only be taken in its man-made form. The form that comes from ground-up cow pineal glands is rarely used, because it may spread disease.
|National Center for Complementary and Alternative Medicine (NCCAM), National Institutes of Health|
|9000 Rockville Pike|
|Bethesda, MD 20892|
The National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health (NIH) explores complementary and alternative healing practices in the context of rigorous science, trains complementary and alternative medicine researchers, and gives out authoritative information.
|National Sleep Foundation|
|1010 North Glebe Road|
|Arlington, VA 22201|
The National Sleep Foundation, an independent nonprofit organization, can provide you with brochures on sleep disorders and a list of accredited sleep disorder clinics.
Other Works Consulted
- Melatonin (2009). Review of Natural Products. St. Louis: Wolters Kluwer Health.
- Rajaratnam SM, et al. (2009). Melatonin and melatonin analogues. Sleep Medicine Clinics, 4: 179–193.
|Primary Medical Reviewer||Kathleen Romito, MD - Family Medicine|
|Specialist Medical Reviewer||Alfred Lewy, MD, PhD - Psychiatry|
|Last Revised||July 7, 2010|
Last Revised: July 7, 2010
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