The present invention provides slow release estradiol-progesteroneformulations that can be used in either contraception or hormone replacementtherapies. The formulations comprise shaped particles of estradiol that is ina hemicrystalline form that exhibits especially low dissolution rates. Theshaped particles comprise estradiol compounded in a 1:1 molar ratio withcholesterol, and are administered in combination with progesterone. The slowrelease formulations of the present invention afford the dual advantages of alow dose estradiol formulation with a low frequency administration regimen.The formulations can be parenterally administered once a month or less often.
