Melatonin is not an amino acid, but it is a hormone that is manufactured in the pineal gland from the
amino acid tryptophan. The pineal gland is a pea-sized organ that sits at the base of the brain.
Melatonin is also available as a dietary supplement. It is the substance that appears to regulate the
"body clock," the physiological changes that relate to day-night changes.
Melatonin levels normally go up when it turns dark, and they are low during daylight hours. This
hormone is also an antioxidant/free-radical scavenger that appears to slow the aging process. The
production of melatonin is high in youth and declines steadily with age. Many signs of aging are
associated with this loss of melatonin production, but cause and effect have not been proven. Large
doses of melatonin have been administered to animals and humans without any known side effects.
Supplements of melatonin, taken at night, often help with insomnia and in overcoming symptoms of
jet lag (for jet lag, it is taken near the bedtime in the new time zone for two or three days before
departure and after arrival). Unlike most medications for insomnia, melatonin is not addictive. When
it is used for insomnia, it does not leave you with any hangover or withdrawal symptoms. Some
animal and human studies have shown benefits in reducing cancer and enhancing immune function. In
animal studies, there is a clear increase in longevity (unfortunately, it is difficult to do longevity
studies in humans). In humans, it has helped in treating depression and also in lowering the eye
pressures in patients with glaucoma.
How to Take Melatonin
Melatonin is commonly available in 3-mg capsules or tablets, and the usual dose is 3-6 mg at
bedtime. Sometimes higher doses are helpful for insomnia and depression. Some people seem to
benefit from taking 10-15 mg of melatonin, without developing any apparent side effects. Larger
doses are being studied for birth control because of melatonin's effect on sexual hormone balance.
Supplements of melatonin are almost all synthetically produced, but the synthetic molecules are
identical to the natural human melatonin. There may be some brands on the market that contain
actual animal pineal gland, but I do not recommend these. They are not as well standardized and
they may contain impurities. Synthetic melatonin supplements are pure white, while the gland
sources usually have some coloration.