17α-Hydroxyprogesterone (17α-OHP), or hydroxyprogesterone (OHP) (INN, BAN), also known as 17α-hydroxypregn-4-ene-3,20-dione, is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many other endogenous steroids, including androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as neurosteroids.