Women on systemic estrogen with an intact uterus require progestogen to prevent endometrial hyperplasia. Micronized progesterone 100 mg at bedtime is the preferred bioidentical option in contemporary guidelines over synthetic progestins, which carry different metabolic and mood profiles.
Allopregnanolone and sleep
Oral micronized progesterone is metabolized to allopregnanolone, a neurosteroid that modulates GABA-A receptors, explaining why many women report improved sleep quality on nightly progesterone versus medroxyprogesterone acetate.
Endometrial protection
PEPI trial data support micronized progesterone for endometrial safety when paired with estrogen. Continuous combined or sequential cycling depends on years since menopause and bleeding tolerance.
Side effects
Drowsiness (take at night), breast tenderness, occasional mood changes. Not for use in peanut allergy (some formulations use peanut oil). Progesterone alone without estrogen is sometimes used off-label for perimenopausal insomnia at lower doses under specialist care.
CLYR Health offers progesterone 100mg capsules as a women's hormone preview SKU paired with estradiol protocols.