What Is Melatonin?

Editor's Choice
Main Category: Sleep / Sleep Disorders / Insomnia
Also Included In: Endocrinology;  Complementary Medicine / Alternative Medicine
Article Date: 02 Aug 2011 - 16:00 PDT

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Melatonin is a hormone, also known as N-acetyl-5-methoxytryptamine, it is a naturally occurring compound found in humans, animals, microbes and plants. In animals and humans, melatonin levels vary during the daily cycle. It is intimately involved in regulating the sleeping and waking cycles. It is sometimes prescribed by doctors for patients with sleep problems. However, in some cases it is not suitable.

In fact, a Spanish study concluded that melatonin is better at getting people to sleep than other medications (Link to article).

Melatonin is also an antioxidant.

Among mammals, melatonin is secreted into the body by the pineal gland from the amino acid tryptophan. It is also known as the "hormone of darkness" because it is secreted when it is dark. Highest levels of melatonin usually occur in humans at bedtime.

A study in the University of Granada, Spain proved that melatonin helps in controlling weight gain, even if the patient does not eat less. It was found to improve the blood lipid profile by reducing triglycerides, rasing HDL cholesterol (good cholesterol) and lowering LDL cholesterol (bad cholesterol) levels (Link to article).

Japanese research found that giving melatonin to women who are trying to get pregnant with IVF (in vitro fertilization) helps improve the quality of the egg and doubles the IVF success rate. Poor egg quality is a major cause of female infertility (Link to article).

According to Medilexicon's medical dictionary, Melatonin is:

"A substance formed by the mammalian pineal gland, which appears to depress gonadal function in mammals and causes contraction of amphibian melanophores; a precursor is serotonin. Melatonin is rapidly metabolized and is taken up by all tissues. It is involved in circadian rhythms."

The following side effects have been associated with melatonin supplements:

• Confusion
• Discomfort in the abdomen
• Headaches
• Nightmares
• Sleepiness during the day
• Sleepwalking

Melatonin may also adversely affect how some medications work, such as anticoagulants (blood-thinning drugs), birth control pills, diabetes drugs, and immunosuppressants.

Melatonin, if prescribed, is usually done so for short periods. Some experts say that treatment for longer than two months might be harmful. Not all experts agree with this.

People taking melatonin should be careful when driving or operating heavy machinery.

Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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