Adrenocorticotropic hormone, also referred to as ACTH, is a chemical substance which is manufactured in the front (anterior) region of the pituitary gland. The pituitary is a small, kidney-bean sized gland located in the center of the brain. The pituitary receives feedback from other organs in the body about the body's chemical state. In response to this information, the pituitary releases more or less of its hormone products, including ACTH. These hormones travel via the blood circulation to various organs and tissues (target organs) throughout the body, where they exert their effects. Because the pituitary gland directs the function of so many other glands and tissues throughout the body, it is often referred to as the "master gland."

ACTH has a number of functions. It is responsible for causing the adrenal gland (a tiny gland perched on top of each kidney) to produce important hormones called...