In a double-blind, randomized dose-response study, 75 women with benign breast disease were administered a written questionnaire in which they scored the severity of premenstrual syndrome (PMS) symptoms before and after two months of treatment with placebo or alpha-tocopherol (150, 300, or 600 IU/day). Controlling for age and pretreatment scores, alpha-tocopherol had a significantly greater effect than placebo, improving three of the four classes of PMS symptoms. These findings suggest that vitamin E supplementation may be of value in women with severe PMS symptoms.