Studies have shown that symptoms, including hot flashes, are relieved with continuous testosterone alone. Testosterone delivered by pellet implant is extremely effective therapy. In addition, it does not have the unwanted side effects of estrogen therapy. Over half of women treated with estrogen (especially the pellet implant) will experience uterine bleeding. If a menopausal patient has bleeding, she must notify her physician and have an evaluation, which may include a vaginal ultrasound and endometrial biopsy. Estrogen also stimulates the breast tissue can cause breast pain and cysts. It also increases the risk of breast cancer. Higher levels of estrogen (in the second half of the menstrual cycle) are needed for pregnancy. Most women feel better with lower levels of estrogen. Almost all symptoms, including hot flashes, are relieved with testosterone pellets alone. A study by Sherwin in 1985 looked at testosterone, testosterone with estradiol, estradiol alone, and placebo. The group of women who responded best had (somatic, psychological and total score) had testosterone alone! The groups that did the worst…estrogen alone and placebo. Higher levels of testosterone were associated with a better response. These results are expected. Testosterone is the major ‘substrate’ for estrogen production in the brain, bones, vascular system, breast, and adipose tissue. Some physicians do not understand this and may insist that estrogen therapy is needed. Excess estrogen can cause anxiety, weight gain, belly fat, tender breasts, emotional liability, symptoms of PMS, and mood swings. Long-term exposure to stronger estrogens like estradiol and Premarin can increase the risk of breast cancer. In addition, there is exposure to many estrogen-like chemicals. Some women (and men) ‘aromatize’ or convert too much testosterone to estradiol, which can interfere with the beneficial effects of testosterone. An ‘aromatase inhibitor’ (i.e. anastrozole) may be prescribed to prevent this. Patients, including breast cancer survivors, may be treated with the combination testosterone-anastrozole.