Hydromadinone acetate (developmental code name NSC-33170), also known as chloroacetoxyprogesterone (CAP), as well as 6α-chloro-17α-acetoxyprogesterone or 6α-chloro-17α-acetoxypregn-4-ene-3,20-dione, is a steroidalprogestin of the 17α-hydroxyprogesterone group that was never marketed.[1][2] It is the C17α acetateester of hydromadinone, which, similarly, was never marketed.[1]