There are multiple metabolic pathways for progesterone. Progestogens are metabolized differently as compared with the fate of endogenous progesterone, and the metabolites are significantly dependent upon the route of administration and the physiologic and pathologic state of the patient. Marked variations between patients have also been observed. Many organs metabolize progestogens, each in its own way. In turn, the metabolites each have different biologic potencies, which include major effects on the central nervous system. Compared with the knowledge base about progesterone metabolism, much less is known about medroxyprogesterone acetate and other C-6 and 19-NOR testosterone-derived progestogens.