The ACTH 15-min test is performed by administering synthetic ACTH and measuring adrenocorticotrophic hormone levels after 15 minutes. The test helps healthcare professionals evaluate baseline adrenal gland function and adrenal response to synthetic ACTH stimulation at 15 minutes. The test evaluates adrenal function, providing insights into the hypothalamic-pituitary-adrenal axis. A rise in ACTH of 35% at 15 and 30 min suggests a pituitary source.