10/14/2026
Not all progesterone is absorbed the same — and when it comes to HRT, that matters. 💊✨
Topical progesterone may be absorbed enough to create noticeable effects like improved sleep or relaxation 😴, but that does not necessarily mean enough is reaching the endometrium to reliably protect the uterine lining when systemic estrogen is being used.
Why is that important? Because estrogen stimulates the endometrium to grow. Without adequate progesterone to oppose that effect, the lining can become overly thickened, increasing the risk of endometrial hyperplasia and, over time, endometrial cancer.
📚 And we have data to support this.
A 48-week study of postmenopausal women using transdermal estrogen with progesterone cream found evidence of inadequate endometrial opposition in 32% of participants.
A 2016 systematic review examining micronized progesterone and endometrial protection concluded that transdermal micronized progesterone does not provide adequate endometrial protection when used with estrogen.
That’s why route, dose, and absorption matter just as much as the hormone itself. 🧬
If you have a uterus and are using systemic estrogen, progesterone needs to provide dependable endometrial protection — not just symptom relief. 🤍
Hope this helps! ✨
Studies:
Vashisht A, et al. BJOG. 2005;112(10):1402–1406.
Stute P, Neulen J, Wildt L. The impact of micronized progesterone on the endometrium: a systematic review. Climacteric. 2016;19(4):316–328. doi:10.1080/13697137.2016.1187123.
