Fifty six patients were recruited from the general gynaecology clinics of the North Staffordshire Hospital Centre, Stoke on Trent, and the Royal Free Hospital, London; from general practitioners' surgeries, and by self referral of volunteers. Before entering the trial they were informed that a non- hormonal preparation containing evening primrose oil was to be compared with a placebo in a blinded study designed to assess the benefits of evening primrose oil in treating menopausal flushes. It was explained that, although “folklore” ascribed great benefits to the use of evening primrose oil, there was no scientific evidence to support this belief. Possible side effects of the oil such as nausea and diarrhoea were also pointed out.