Melatonex

Melatonin is a hormone primarily released by the pineal gland at night, and has long been associated with control of the sleep–wake cycle.[2][4] In vertebrates, melatonin is involved in synchronizing circadian rhythms, including sleep–wake timing and blood pressure regulation, and in control of seasonal rhythmicity including reproduction, fattening, moulting and hibernation.[5] Many of its effects are through activation of the melato... [wikipedia]