Encyclopedia of Drugs and Addictive Substances | Melatonin - What Kind of Drug Is It?

What Kind of Drug Is It?

Melatonin is a dietary supplement sold without a prescription at U.S. health stores or through Web sites. It is sold primarily as a sleep aid because it induces sleep. Researchers have studied melatonin's potential benefits for certain conditions, such as insomnia (difficulty sleeping); jet lag; and even cancer (the uncontrolled, abnormal growth of cells that can lead to serious illness and death).

However, taking melatonin supplements has not been proven by scientific studies to be effective for any condition. Much more research needs to be done to prove the positive claims of melatonin use. Also, because it is considered a dietary supplement, it is not regulated by the U.S. Food and Drug Administration (FDA). This means that the supplements are not produced under the strict guidelines of the FDA, so their side effects and long-term effects are not clearly known.

Melatonin is a hormone—a substance created by the body to control certain bodily functions. It is found naturally in humans and other animals. It is secreted by the pineal (PY-nee-uhl) gland, which is located in the middle of the brain. Melatonin helps to regulate when animals, including humans, fall asleep and when they wake up. This sleep/wake cycle is known as the circadian rhythm (sir-KAY-dee-in RIH-thum), the twenty-four-hour sleep/wake cycle in humans and other animals. Some people believe that taking melatonin supplements can help alleviate problems that can occur when this cycle is disrupted.