Melatonin occurs naturally in certain places. Not only is it synthesised by the human body, but certain plants also produce the valuable hormone.
Body: Melatonin is a hormone produced naturally in the body, mainly by the pineal gland (epiphysis) in the brain. In addition to the pineal gland, melatonin is also synthesised to a lesser extent in certain parts of the gut and retina.
Plants: Melatonin has also been found in certain plants. These include various herbs, seeds and fruits. For example, melatonin has been found in the skin of certain red grapes (9).