Adrenocorticotropic hormone (ACTH or corticotropin) is a polypeptide hormone, secreted from the anterior lobe of the pituitary gland in response to corticotropin-releasing hormone (CRH) from the hypothalamus. It stimulates the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also mineralcorticoids and sex steroids (androgens). Together with ACTH the hormones lipotropin, melanocyte-stimulating hormone (MSH), β-endorphin and met-enkephalin are also released.

See also: Addison's disease, Nelson's syndrome, Congenital adrenal hyperplasia, Cushing's syndrome, adrenoleukodystrophy, ectopic tumor.\n