ɪɾ ɪz mˈoːɹ spəsˈɪfɪkli ɐ dᵻɹˈɪvətˌɪv ʌv nˌoːɹɪθˈɪstɚɹˌoʊn sˈɛvəntˌiːn ˈælfəˈɛθɪnˌaɪl nˈaɪntiːnnˌɔːɹɾɪstˈɑːstɚɹˌoʊn ænd ɪz ɐ mˈɛmbɚɹ ʌvðə ɡˈɑːneɪn ˈeɪtiːnmˈɛθaɪlstɹˌeɪn sˈʌbɡɹuːp ʌvðə nˈaɪntiːnnˌɔːɹɾɪstˈɑːstɚɹˌoʊn fˈæmɪli ʌv pɹoʊdʒˈɛstɪnz.
It is more specifically a derivative of norethisterone (17α-ethynyl-19-nortestosterone) and is a member of the gonane (18-methylestrane) subgroup of the 19-nortestosterone family of progestins.