05/12/2025
Progesterone isn’t just about periods—it’s a neurosteroid. And in menopause, when levels plummet, that matters. A lot.
A new 2025 study published in the Journal of Menopausal Medicine followed peri- and postmenopausal Japanese women who were newly prescribed hormone replacement therapy (HRT) with estradiol (E2) and oral micronized progesterone (MP). These were real women experiencing real sleep disturbances—nearly 87% were classified as poor sleepers at baseline using the Pittsburgh Sleep Quality Index (PSQI).
Here’s what happened:
After just 1 month on HRT, women had statistically significant improvements in global PSQI scores and self-reported sleep quality. Those with the worst sleep efficiency at baseline improved the most. And these improvements continued at 3 months.
Why does this matter?
Oral micronized progesterone crosses the blood-brain barrier and is converted into allopregnanolone, a potent positive allosteric modulator of GABA-A receptors. Translation: it calms the brain, promotes deeper sleep, and reduces sleep latency. This is not just a sedative effect—it’s part of progesterone’s role as a central nervous system hormone.
While this was a small, open-label study, it adds to the growing body of evidence that bioidentical hormone therapy is not just about hot flashes. It can improve brain health, sleep architecture, and quality of life—especially when tailored with the right form, route, and dose.
Citation: Ogawa M et al. J Menopausal Med. 2025 Apr.
“Changes in Sleep Quality after Hormone Replacement Therapy with Micronized Progesterone in Japanese Menopausal Women.”
