Cosyntropin (brand name: Cortrosyn) is a medication used to perform the ACTH Stimulation Test, which assesses the adrenal cortex’s ability to produce cortisol in response to ACTH. ACTH (Adrenocorticotropic Hormone) is produced by the pituitary gland and stimulates the adrenal glands. Cosyntropin is administered by intravenous (IV) or intramuscular (IM) injection. This test is valuable in diagnosing adrenal and pituitary disorders, including Addison’s disease and pituitary insufficiency. Always consult your healthcare provider for more information on the ACTH Stimulation Test and its interpretation.