ACTH secretion is regulated by a feedback loop involving the hypothalamus, pituitary gland, and adrenal glands. When cortisol levels drop, the hypothalamus releases CRH (Corticotropin-Releasing Hormone), which tells the pituitary to release ACTH. High cortisol levels then signal the pituitary to stop ACTH release.

Regulation Overview

• Low cortisol → More ACTH released.
• High cortisol → ACTH release decreases.‍
• Controlled by: Hypothalamic - pituitary - adrenal (HPA) axis.