Methods for treating or reducing the likelihood of acquiring estrogen-related (e.g. estrogen-exacerbated) diseases including endometriosis include administering to a patient a selective estrogen receptor modulator (SERM), in combination with inhibiting ovarian secretions, e.g., by administering an LHRH agonist or antagonist. In some embodiments, a precursor of sex steroids, said precursor being selected from the group consisting of dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), androst-5-ene-3&bgr;,17&bgr;-diol (5-diol), and androstenedione or a compound transformed into one of these, is also administered