ʻO Melatonin kahi hormone i hūnā ʻia e ka pineal gland o ka lolo i nā mammals a me nā kānaka.No ka mea hiki iā ia ke hoʻomāmā i nā cell e hana i ka melanin, no laila ka inoa melatonin, ʻike ʻia hoʻi ʻo pineal hormone, melatonin, melatonin.Ma hope o ka hoʻohui ʻia ʻana o ka melatonin a mālama ʻia i loko o ke kino pineal, hoʻoulu ʻia ke aʻalolo aloha i loko o nā pūnae pineal e hoʻokuʻu i ka melatonin.ʻO ka huna ʻana o ka melatonin he ʻano circadian rhythm, kahi i kāohi ʻia i ke ao a me ka hana i ka pō.Hiki i ka Melatonin ke kāohi i ka axis hypothalamic-pituitary-gonadal, e hoʻemi i ka ʻike o ka gonadotropin hoʻokuʻu i ka hormone, gonadotropin, luteinizing hormone a me ka follicle stimulating hormone, a hiki ke hana pololei i nā gonads e hōʻemi i ka ʻike o ka androgen, estrogen a me progesterone.