In a randomized, double-blind, dose-response study, alpha-tocopherol significantly ameliorated symptoms in three of the four classes of the premenstrual syndrome (PMS). Alpha-tocopherol treatment had no significant effect on serum concentrations of testosterone, dehydroepiandrosterone sulfate (DHEA-S), estradiol, and progesterone. However, independent of treatment, a significant correlation emerged between temporal changes in one PMS category and changes in DHEA-S concentrations. These results suggest that improvement in PMS severity is not mediated through direct effects of alpha-tocopherol on serum steroids. Androgens, however, may play a role in some PMS symptomatology.