Abstract: The present invention relates to a method of using 17.alpha.-dihydroequilenin and metabolic conjugates thereof to prevent and reduce atherogenesis in males and females without causing endometrial proliferation in females and without producing feminizing changes in males. 17.alpha.-dihydroequilenin was evaluated for its effects on plasma lipid and lipoprotein, glucose, insulin concentrations, coronary artery vasomotor function, and reproductive organ and mammary gland proliferation in atherosclerotic mammals. 17.alpha.-dihydroequilenin was found to prevent endothelium-dependent vasoconstriction in males (p<0.05) and ovariectomized females (p<0.08). 17.alpha.-dihydroequilenin treatment increased plasma apolipoprotein A-l concentrations (p<0.05) and lowered fasting insulin concentrations (p<0.05) without changing fasting plasma glucose concentrations in males. 17.alpha.-dihydroequilenin had no other effects on plasma lipid and lipoprotein concentrations in either males or females. Also, 17.alpha.