. The goal of this project is to develop a once-daily, oral progesterone formulation for hormone replacement therapy as indicated for postmenopausal management, oral contraception, amenorrhea, and pregnancy maintenance. The specific aims are: 1) to refine a formulation of micronized oral progesterone in a novel proprietary polymer matrix drug delivery vehicle for clinical evaluation; 2) to test dosage forms of oral progesterone for ability to deliver steady therapeutic blood levels at once daily administration, with good stability of potency; and 3) to evaluate this formulation for further clinical development with additional refinement of dosage, if necessary. It is asserted that an oral form of natural progesterone would be an excellent alternative to the currently used synthetic progestins which exhibit considerable side-effects. It is further expected that an oral formulation would be more acceptable to patients than rectal, parenteral, or vaginal progesterone formulations.