: Melatonin is an indoleamine neurohormone found across plants and animals, produced endogenously from serotonin (5-HT) and secreted in animals as a regulatory signal for synchronization of the circadian rhythm and the sleep-wake cycle.
: M 1558 (OTTO) Melatonin, 99% Cas 73-31-4 - used as an antioxidant. Melatonin is involved in many biological functions such as circadian rhythm, sleep, the stress response, aging, and immunity.