Abstract
Two hundred women with breast cysts proven by aspiration were entered into a randomized double-blind trial of evening primrose oil (Efamol) at a dose of 3 g daily by mouth or placebo for a year. Neither the number of patients developing recurrent cysts nor the total numbers of recurrent cysts were significantly reduced in the Efamol treated group compared with the placebo treated group. Efamol treatment was well-tolerated as only six women dropped out because of side effects, three in both the Efamol and placebo treated groups. There was no difference in the numbers of patients in each group who complained of side effects, and no haematological suppression or alteration of renal or hepatic function during the treatment period.
