How it  Melatonin is a natural hormone (produced by the pineal gland) that seems to regulate your internal clock.
Melatonin is one of many hormones secreted by the pineal gland.
mnli hypothesis: Melatonin is one of many hormones secreted by the pineal gland. premise: How it  Melatonin is a natural hormone (produced by the pineal gland) that seems to regulate your internal clock.