Progesterone — Bioidentical Progesterone — Endometrial Protection and Sleep

Progesterone in HRT — Why Bioidentical Matters

Progesterone serves two critical roles in HRT: it provides endometrial protection for women with a uterus (unopposed estrogen without progesterone increases endometrial cancer risk), and it has significant neurological effects via GABA modulation that produce sleep-promoting and anxiolytic benefits. The form of progesterone prescribed matters clinically: micronized progesterone (bioidentical) is molecularly identical to endogenous progesterone, while synthetic progestins (medroxyprogesterone acetate, norethindrone) have different receptor binding profiles and are associated with more side effects including mood changes, bloating, and potentially different cardiovascular effects.

Our providers prescribe oral micronized progesterone (Prometrium or compounded equivalent) taken at bedtime — capitalizing on its sedating neurological effects for sleep improvement while providing endometrial protection. For women who prefer transdermal or topical progesterone, compounded progesterone cream is an option, though the systemic absorption and endometrial protective efficacy of topical progesterone is less established than oral.