cyproterone

Cyproterone, also known by its developmental code name SH-80881, is a steroidal antiandrogen which was studied in the 1960s and 1970s but was never introduced for medical use. It is a precursor of cyproterone acetate (CPA), an antiandrogen, progestin, and antigonadotropin which was introduced instead of cyproterone and is widely used as a medication. Cyproterone and CPA were among the first antiandrogens to be developed.

The term cyproterone is often used as a synonym and shorthand for cyproterone acetate, and when the term occurs, what is almost always being referred to is, confusingly, CPA and not actually cyproterone. Cyproterone itself, unlike CPA, was never introduced for medical use and hence is not available as a medication.