Melatonin

melatonin /mel·a·to·nin/ (mel?ah-to´nin) a catecholamine hormone synthesized and released by the pineal body; in mammals it influences hormone production and in many species regulates seasonal changes such as reproductive pattern and fur color. In humans it is implicated in the regulation of sleep, mood, puberty, and ovarian cycles and it has been tried therapeutically for insomnia, jet lag, and other conditions.

---

mel·a·to·nin (ml-tnn)

n.

A hormone derived from serotonin and produced by the pineal gland that stimulates color change in the epidermis of amphibians and reptiles and that is believed to influence estrus in mammals.

---

Melatonin

A naturally occurring hormone involved in regulating the body's "internal clock."

Mentioned in: Jet Lag, Seasonal Affective Disorder

---

melatonin (meˈ·l·tōˈ·nin),

n hormone secreted from the pineal gland thought to regulate circadian rhythms. Also used in supplement form as a sleep aid.

---

melatonin

(mel´tō´nin),
n the only hormone secreted into the bloodstream by the pineal gland. It appears to inhibit numerous endocrine functions, including the gonadotropic hormones, and to decrease the pigmentation of the skin.

---

melatonin

an indoleamine hormone synthesized and released by the pineal body during the hours of darkness; it may have a role in the control of the regulation of gonadotropin release.