The invention discloses a steroid compound having the formula (1), wherein dotted bonds represent optional double bonds; R6 is H, ═CH2, or —CH3, or —CH2—CH3; R7 is H, C1-4-alkyl, C2-5 alkenyl or C2-5-alkynyl, wherein the alkyl, alkenyl or alkynyl group may be substituted with 1 to 3 halogen atoms independently chosen from the group of fluorine or chlorine atoms; R11 is H, C1-4-alkyl, C2-4-alkenyl, C2-4-alkynyl or C1-4-alkylidene, wherein the alkyl, alkenyl, alkynyl or alkylidene group may be substituted with 1-3 halogen atoms independently chosen from the group of fluorine or chlorine atoms; E represents together with carbon atoms 16 and 17 of the steroid skeleton a four to seven-membered ring, said ring being α and in cis-configuration with respect to the steroid skeleton, optionally comprising one or two endocyclic bonds; or a prodrug thereof. Such compounds can be used in therapy and for methods for selective modification of the activity of estrogen receptors.