Amylin, also known as islet amyloid polypeptide (IAPP), is a peptide hormone which is deficient in patients with diabetes mellitus (DM). Amylin is co-secreted with insulin from the pancreatic β-cells. It inhibits glucagon secretion, delays gastric emptying, and thus acts as a satiety agent.  Amylin peptide is capable of forming aggregates, and pancreatic amyloid plaques are present in 90% of patients with DM. Formation of these plaques may be inhibited by insulin via the formation of heteromolecular complexes. Amylin is also involved in adiposity signalling and body weight regulation.

Amylin is expressed in the human placenta during pregnancy where it may help regulate food intake by both the mother and foetus, and is involved in foetal development of bone, kidneys and pancreas.