The results from our pilot study show that gamolenic acid provided by evening primrose oil, although popularly believed to alleviate vasomotor symptoms of the menopause, offers no benefit over placebo. This may be because metabolites of evening primrose oil provide high concentrations of prostaglandins which decrease the affinity of ligands such as oestrogens and other hormones for their receptors.12 In addition, several experiments have shown prostaglandins acting at the hypothalamus stimulate the release of follicle stimulating hormone and luteinising hormone.5 High concentrations of these pituitary gonadotrophins have long been implicated in the production of menopausal vasomotor disorders, although the exact mechanism remains elusive. Based on the data from this small pilot study and on the lack of a hypothetical rationale for using gamolenic acid, we cannot support the use of evening primrose oil in the treatment of menopausal hot flushes. Larger studies are required.