15β-Hydroxycyproterone_acetate
15β-Hydroxycyproterone acetate
Chemical compound
15β-Hydroxycyproterone acetate (15β-OH-CPA) is a steroidal antiandrogen and the major metabolite of cyproterone acetate (CPA).[1][2][3] It is formed from CPA in the liver by hydroxylation via the cytochrome P450 enzyme CYP3A4.[1][2][3] During therapy with CPA, 15β-OH-CPA circulates at concentrations that are approximately twice those of CPA.[4] 15β-OH-CPA has similar or even greater antiandrogen activity compared to CPA.[5] However, it has only about one-tenth of the activity of CPA as a progestogen.[6] 15β-OH-CPA also shows some glucocorticoid activity, similarly to CPA and unesterified cyproterone.[7][8]