A dose of testosterone may be a good thing for post-menopausal women undergoing hormone replacement therapy. Estrogen mixed with an equal amount of methyl-testosterone, also known as androgen, improved sexual desire and response in women who were dissatisfied with estrogen alone, according to a study in the October issue of The Journal of Reproductive Medicine. “Giving estrogen alone to menopausal women helped a little bit, but gradually over time the effectiveness was lost,” says Philip Sarrel, M.D., professor of obstetrics and gynecology and of psychiatry, and principal investigator for the study. “What we found in our study was the missing part—the lack of androgen replacement.” Side effects and failure of the treatment to meet the patient’s needs are the most common reasons women give for discontinuing hormone replacement therapy.