Dr. Nachtigall is an endocrinologist and physician who defends the use of estrogen replacement therapy (ERT) for menopausal women who suffer severe symptoms and for whom there are no contraindications. Her defense is based in part on a ten-year double-blind study of 168 women, half on ERT, half on placebo. The reader is not told very much about these women except that they were all chronic disease patients to start with. That, plus the small number, seems hardly convincing evidence to defend a highly controversial practice. In fairness, Dr. Nachtigall urges caution and she lists the many contraindications such as liver problems, history of breast cancer, hypertension, diabetes, etc. In the study and in her treatment of patients, she also introduces progesterone for one week every month following three week's estrogen therapy. This in effect reintroduces menstrual periods and is the doctor's answer to the need to slough off the uterine lining built up by the estrogen which may encourage endometrial cancer to develop. The virtues of estrogen are explained at length as the author discusses all the physical and psychological changes that occur during premenopause and menopause. This information is useful, often repetitive. The style--sometimes slangy, sometimes employing medical phrases--also leaves something to be desired. As a source for hard fact--yes, with discretion. As a convincing argument for ERT, no.