This invention provides tissue selective estrogens of formula I having the structure wherein: R1 and R2 are independently, hydrogen, alkyl chain of 1-6 carbon atoms, benzyl, acyl of 2-7 carbon atoms, benzoyl, X is hydrogen, alkyl of 1-6 carbon atoms, CN, halogen, trifluoromethyl, or thioalkyl of 1-6 carbon atoms; n=1-3; with the proviso that at least one of R1 or R2 are not hydrogen, alkyl chain of 1-6 carbon atoms, benzyl, acyl of 2-7 carbon atoms, or benzoyl; or a pharmaceutically acceptable salt thereof.