Corticotropin, also known as adrenocorticotropic hormone (ACTH), is a hormone produced by the pituitary gland. It plays a crucial role in stimulating the adrenal glands to release cortisol, a hormone that helps regulate metabolism, immune response, and stress. Corticotropin is often used in medical settings to diagnose and treat conditions related to adrenal insufficiency and other disorders. It can be administered as an injection and is sometimes used in tests to assess the function of the adrenal glands and the hypothalamic-pituitary-adrenal axis.