Cyproterone is a synthetic progestin and strong anti-androgen typically used in the formulation of Cyproterone Acetate. Cyproterone is often used in palliative care to slow down androgen-receptive cancers and to reduce androgen levels in natal women with conditions such as Polycystic Ovary Syndrome and Congenital Adrenal Hyperplasia. Particularly within Europe it is also used as a frontline anti-androgen in transfeminine HRT. Historically it has been prescribed at doses of 50-100mg/day, however more recent studies have shown it is fully effective in that role at doses as low as 10mg/day.

Cyproterone has a statistically associated risk of Meningiomas, prolactin levels should be monitored in blood tests when taking it.