Seventeen females with a history of hot flushes, perspiration, and amenorrhea of at least 6 months' duration, and a serum FSH level exceeding 40 IU/l entered a cyclic treatment with 17 beta-estradiol and estriol combined with norethsterone (Trisekvens, Novo). Each patient took part in three experimental sessions, six weeks apart, in which stress was induced by mental performance tests. To permit separation of treatment and habituation effects the patients were randomly assigned to one of two groups, Group 1 starting therapy after the first, Group 2 after the second session. Treatment eliminated hot flushes and perspiration and reduced serum FSH levels without causing changes in blood pressure or heart rate. There was no correlation between hormonal treatment and excretion of catecholamines during stress. Testosterone and androstenedione serum levels remained unchanged during therapy. Self-reports showed that tiredness, headache, tension and anxiety were significantly reduced following treatment.