20-oxo steroid acetate ester 3-oxo-Δ4 steroid cyproterone acetate http://purl.bioontology.org/ontology/MESH/D017373 http://purl.bioontology.org/ontology/RXNORM/22054 http://purl.bioontology.org/ontology/SNOMEDCT/126120000 http://purl.obolibrary.org/obo/CHEBI_50743 http://purl.obolibrary.org/obo/NCIT_C1059 https://en.wikipedia.org/wiki/Cyproterone_acetate https://www.wikidata.org/wiki/Q426185 An agent with anti-androgen and progestational properties. It shows competitive binding with dihydrotestosterone at androgen receptor sites. CPA G03HA01 The acetate salt of a synthetic steroidal antiandrogen with weak progestational and antineoplastic activities. Cyproterone binds the androgen receptor (AR), thereby preventing androgen-induced receptor activation in target tissues and inhibiting the growth of testosterone-sensitive tumor cells. This agent also exerts progestational agonist properties at the level of the pituitary that reduce luteinizing hormone (LH), resulting in reductions in testicular androgen secretion and serum testosterone levels. Treatment with cyproterone alone results in incomplete suppression of serum testosterone levels. chlorinated steroid progestogen ester Cyproterone acetate or spironolactone in lowering testosterone concentrations for transgender individuals receiving estradiol therapy