Synonyms: 19-Nor-17a-pregn-5(10)-en-20-yn-3-one,17-hydroxy- (6CI,8CI); 13-Methyl-17-ethynyl-17-hydroxy-1,2,3,4,6,7,8,9,11,12,13,14,16,17-tetradecahydro-15H-cyclopenta[a]phenanthren-3-one;17-Hydroxy-19-nor-17a-pregn-5(10)-en-20-yn-3-one; 17a-Ethinyl-17b-hydroxy-D5(10)-estren-3-one; 17a-Ethynyl-17-hydroxy-5(10)-estren-3-one; 17a-Ethynyl-17b-hydroxy-5(10)-estrene-3-one; 17a-Ethynyl-17b-hydroxy-D5(10)-estren-3-one; 17a-Ethynylestr-5(10)-ene-17b-ol-3-one; 17a-Ethynylestra-5(10)-ene-17b-ol-3-one; 17b-Hydroxy-19-nor-17a-pregn-5(10)-en-20-yn-3-one;3-Oxo-17b-hydroxy-17a-ethynyl-5(10)-estrene; Enidrel;NSC 15432; Norethinodrel; Norethynodrel; Noretynodrel; SC 4642