Sisu Liquid MelatoninHighlights of Liquid Melatonin Liquid form for flexible dosing & rapid absorption Pure, vegan source High dose Our daily sleep wake cycle is regulated by our circadian rhythm, the physical, mental and behavioral changes in our body that follow roughly a 24 hour cycle, responding primarily to light and darkness in our environment. The pineal gland at the base of the brain releases the sleep hormone, melatonin, when it gets dark, and suppresses