During the past few years, the endocrine treatment of the menopause syndrome has become established on a firm, rational basis. This has been made possible by studies of numerous investigators clarifying the hormonal mechanism responsible for the menopausal symptoms and by the researches of the sterol chemists which made available highly potent preparations of ovarian hormones. The traditional concept of the menopause as an aberration of somatic function, predominantly psychogenic in origin and requiring only sedation and psychotherapy, has given way to the realization that the menopausal symptoms are primarily a manifestation of a hormone deficiency caused by a waning or cessation of ovarian activity and that rational therapy should consist of supplying the patient with the hormone she lacks. The therapeutic results obtained with estrogens in the menopause constitute one of the most gratifying and dramatic achievements of modern medicine. However, by virtue of the fact that administering estrogens