User:Mr. Ibrahem/Melatonin

Melatonin is a hormone primarily released by the pineal gland that regulates the sleep–wake cycle. As a dietary supplement, it is often used for the short-term treatment of trouble sleeping, such as from jet lag or shift work, and is typically taken by mouth. Evidence of its benefit for this use, however, is not strong. A 2017 review found that sleep onset occurred six minutes faster with use but found no change in total time asleep. The melatonin receptor agonist medication ramelteon may work as well as melatonin supplements.

Side effects from supplements are minimal at low doses for short durations. Side effects may include sleepiness, headaches, nausea, diarrhea, and abnormal dreams. Use is not recommended during pregnancy or breastfeeding. Use is also not recommended in those with liver problems.

In animals (including humans), melatonin is involved in synchronizing the circadian rhythm, including sleep–wake timing, blood pressure regulation, and seasonal reproduction. Many of its effects are through activation of the melatonin receptors, while others are due to its role as an antioxidant. In plants, it functions to defend against oxidative stress. It is also present in various foods.

Melatonin was discovered in 1958. It is sold over the counter in Canada and the United States; in the United Kingdom, it is a prescription-only medication. A month's supply costs about US $1 to 4 in the United States. In the United Kingdom a month's supply costs the NHS about 15 pounds. It is not approved by the US Food and Drug Administration (FDA) for any medical use. In Australia and the European Union, it is indicated for difficulty sleeping in people over the age of 54. In the European Union, it is indicated for the treatment of insomnia in children. It was approved for medical use in the European Union in 2007.