Disclaimer: I am not a medical professional and this is not medical advice.
I’ve previously covered anecdotal reports from HRT provider Dr. Will Powers on the role of relative levels of different kinds of estrogens in producing effective physical feminization in trans women. Estrogen is not one thing; estradiol (E2), the most common estrogen used in trans women’s HRT, is just one kind. Another form of estrogen, estrone (E1), binds to estrogen receptors but is much weaker in its effects than estradiol, and excessive levels of estrone compared to estradiol can crowd out estradiol at these receptors, inhibiting its feminizing effects. However, lab tests for trans women’s estrogen levels often only measure estrogen as a whole, rather than estradiol and estrone separately. Because of this, what appear to be adequate levels of estrogen may in reality consist mostly of less effective estrone rather than estradiol. Continue reading “New data on trans women’s estradiol/estrone ratios for different routes of administration of HRT”