A vertebrate hormone of the pineal gland that produces lightening of the skin by causing concentration of melanin in pigment-containing cells and that plays a role in sexual development and maturation.

褪黑色素(松果腺脊椎激素的一种，能使色素细胞的黑素聚集而使皮肤变白。褪黑色素在性发育及成熟中亦产生作用)。