Anastrozole is a non-steroidal aromatase-inhibiting drug approved for the treatment of breast cancer after surgery, as well as for metastasis in both píe and post-menopausal women. The severity of breast cancer can be increased by estrogen, as sex hormones cause hyperplasia, and differentiation at estrogen receptorsites. Anastrozole works by inhibiting the synthesis of estrogen. Anastrozole has been tested for reducing estrogens, including estradiol in men. Excess estradiol in men can cause benign prostatic hyperplasia, gynecomastia, and symptoms of hypogonadism. It can also contribute to increased risk of stroke, heart attack, chronic inflammation, prostate enlargement and prostate cancer. Some athletes and body builders use anastrozole as part of their steroid cycle to reduce and prevent symptoms of excess estrogen–gynecomastia, emotional lability and water retentiOn. Study data suggests dosages of 0.5 mg to 1 mg a day reduce serum estradiol by approximately 50% in men, which differs inpostmenopausal women.