<unk> , also known as 17α-ethynyl-18-methyl-19-nor-δ15-testosterone, as well as 17α-ethynyl-18-methylestra-4,15-dien-17β-ol-3-one or 13β-ethyl-18,19-dinor-17α-pregna-4,15-dien-20-yn-17β-ol-3-one, is a synthetic estrane steroid and a derivative of testosterone. 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.<unk>  is almost identical to levonorgestrel in terms of chemical structure, differing only in having an additional double bond between the C15 and C16 positions, and for this reason is also known as δ15-norgestrel or as 15-dehydronorgestrel.
Gestodene
Hexestrol
Mestanolone
Formestane
Fosfestrol
Dimestrol
Gestrinone
Dienestrol