Hrt Interactions

Smoking speeds up how the liver breaks down estradiol, lowering circulating estrogen and reducing the effectiveness of oral hormone replacement therapy. It also adds to the blood-clot risk that oral HRT already carries.

The idea that soy isoflavones add an extra estrogen dose on top of HRT is not supported by the best human evidence; pooled randomized-trial data show isoflavones do not meaningfully raise estradiol, suppress FSH, or thicken the endometrium in postmenopausal women.