Premenstrual syndrome. A double-blind cross-over study of treatment with dydrogesterone and placebo.

A double-blind, cross-over, placebo-controlled study of dydrogesterone (10 mg b.d.) in the treatment of premenstrual syndrome is described. Two groups of women were studied: secondarily referred hospital clinic patients, and self-referred patients. Only one-third of patients screened completed the study. All patients showed significant improvements in symptom scores during the course of the study, the only significant difference between placebo- and dydrogesterone-treated patients being an increase in frequency of breast tenderness and a decrease in pain with menstrual bleeding in the latter.