To Sara Reuning: Re Leuprolide Acetate ( Lupron ) Lupron is a synthetic gonadotropin releasing factor agonist. It occupies this receptor (and desensitizes it) in the pituitary and shuts off normal gonadotropin-releasing hormone secretion, hence no LH or FSH hormones are secreted from the pituitary. In about two weeks, all testosterone and estrogen secretion has fallen to menopausal levels. It would undoubtedly stop lactation as well. As for the treatment of fibroid tumors, Lupron is a good choice because the fibroid tissue is extremely estrogen-dependent. Side Effects: It induces a menopausal-like syndrome including hot flashes, hence it is also indicated for endometriosis. Regards Tom Hale