Melatonin is a hormone produced by the pineal gland, a small gland in the brain, which plays a role in the body’s sleep cycles. The brain makes this neurohormone from the amino acid tryptophan. Very small amounts of melatonin are found in foods, although the amount that the diet contributes to the levels of melatonin in the body is not clear.
What you need to know before taking melatonin
Melatonin (N-acetyl-5-methoxytryptamine) is a neurohormone that is produced mainly by the pineal gland, located behind the third ventricle in the brain. In the synthesis of melatonin, tryptophan is hydroxy 5-hydroxytryptophan, which in turn is 5-hydroxytryptamine (serotonin). Serotonin becomes the precursor of melatonin and metabolite serotonin by the enzyme n-acetyl-n transferase.