NEWS: ethinyl estradiol gets up to some odd tricks

While this applies only to a small subset of menopausal women, we just recently read two interesting research articles about ethinyl estradiol, a synthetic estradiol used most typically in oral contraceptive but also used by some women in menopause who need a synthetic estradiol.



In the first study, "Formation of Ethinyl Estradiol in Women during Treatment with Norethindrone Acetate," it appears that taking this progestin, used by some women to suppress endo in surgical menopause, allows the body to create this form of estrogen (that is, it's partly metabolized into this estrogen). The implication, we think, is that a woman's total estrogen exposure might thus be miscalculated. That's not of functional significance unless one wants to avoid estrogen exposure or when a woman using NET-A changes HRTs and suddenly finds her estrogen needs seem wonky. How much? It's probably pretty individual, but point your endocrinologist to this article and ask for more interpretation if this affects your HRT regimen and concerns.



In the second, "Effects of oral and trans-vaginal ethinyl estradiol on hemostatic factors and hepatic proteins in a randomized, cross-over study," researchers report that oral and vaginal delivery of ethinyl estradiol makes no difference in clotting risk factors. This is pretty much different from what current thinking is on other estrogens, where transdermal delivery is less stimulating of these factors when compared to oral delivery. Again, it's like to affect only a few women, but it does suggest that those at higher risk for clotting (smokers, those with elevated cardiovascular risk profiles or a stroke or clotting history) might want to consider other this estrogen for their HRTs, as might women who require an oral estrogen for some reason but are wary of the effects of oral estradiol or CEEs.