This study discussed the role on estrogen on preventing neurodegeneration. This important function of estrogen is one of the reasons I warn men not to lower estradiol too much: we need it for healthy brain function and to protect against neurological degeneration. Yes, excess estradiol may increase breast tissue size, cause water retention, moodiness and erectile dysfunction and some men need to lower it while on testosterone replacement therapy with aromatase inhibitors. But overdosing these agents can wipe one's estradiol. Bone density loss, worse hair and skin health, and cognitive issues may appear the. So, be conservative and retest a month after starting anastrazole or tamoxifen (two of the several aromatase inhibitors available). Adjust dose so that estradiol is not under 15-20 pg/dL or over 35 pg/dL. Some men only require 0.5 mg of anastrazole 2-3 times a week after induction therapy of 1 mg per day for 3 days. However, no optimum dosing protocol has been studied in men on testosterone who experience large estradiol increases on therapy.