Leptin (116-130) is an active peptide fragment of leptin that increases levels of luteinizing hormone and prolactin. Leptin is an endogenous peptide that binds leptin receptors; it is involved in feeding behavior and energy homeostasis. Leptin exhibits anorexigenic, antihypertensive, and neuroprotective activities. Leptin induces secretion of α-melanocyte-stimulating hormone (α-MSH) and gonadotropin-releasing hormone (GnRH). Leptin (116-130) also decreases release of corticosterone and adrenocorticotropic hormone (ACTH) from the pituitary gland. In animal models, this peptide fragment of leptin inhibits human chorionic gonadotropin (hCG)-stimulated testosterone secretion as well as luteinizing hormone and follicle-stimulating hormone (FSH) secretion. In obese and diabetic mice, leptin (116-130) decreases blood glucose levels.