Leptin (from
Greek λεπτός
leptos, "thin"), the "satiety hormone," is a
hormone made by
adipose cells that helps to regulate
energy balance by inhibiting hunger. Leptin is opposed by the actions of the hormone
ghrelin, the "hunger hormone". Both hormones act on receptors in the
arcuate nucleus of the
hypothalamus to regulate appetite to achieve
energy homeostasis. In obesity, a decreased sensitivity to leptin occurs, resulting in an inability to detect satiety despite high energy stores.