Amlintide (amylin) is a 37 amino acid peptide hormone that is closely related to calcitonin gene-related peptide (CGRP). Amylin was originally discovered as the main component of islet amyloid deposition in patients with type 2 diabetes. Amylin and CGRP share a receptor and are reported to have several similar biological actions. Amylin's major role is as a glucoregulatory hormone, and it is an important regulator of energy metabolism in health and disease. Other amylin actions have also been reported, such as on the cardiovascular system or on bone. Amylin acts principally in the circumventricular organs of the central nervous system and functionally interacts with other metabolically active hormones such as cholecystokinin, leptin, and estradiol. Amylin has been shown to have binding sites within the renal cortex in the area of the juxtaglomerular apparatus. Amylin has been shown to activate the rennin angiotensin aldosterone system. The amylin-based peptide, pramlintide, is used clinically to treat type 1 and type 2 diabetes. Pramlintide exhibits similar biologic activity to that of amylin. Clinical studies in obesity have shown that amylin agonists could also be useful for weight loss, especially in combination with other agents. Amylin is one of the few established gut/pancreatic hormones that has demonstrated durable, safe, tolerable, and clinically meaningful weight loss in humans.