Cosyntropin is a medication that is used in stimulation tests in the medical diagnosis of certain disorders. Cosyntropin is a synthetic or man-made derivative of the natural hormone ACTH. Under normal circumstances, the pituitary gland produces ACTH hormone which stimulates the adrenal glands. The adrenal glands then produce steroids such as cortisone and hydrocortisone and androgens. The common brand name is Cortrosyn while Cosyntropin is a generic hormonal drug.