Cimicifuga racemosa: a systematic review of its clinical efficacy.

Cimicifuga racemosa has long been advocated as an alternative to hormone-replacement therapy. However, recent experimental studies and a clinical trial have raised some questions on its utility. The aim of this systematic review is principally to summarise the trial evidence regarding the efficacy of C. racemosa in the treatment of menopausal symptoms. In addition, we also explore the evidence relating to the mechanism of action of this herbal medicine.Searches of seven computerised databases were performed to identify all randomised clinical trials (RCTs) on C. racemosa as well as animal and in vitro experiments. No language restrictions were imposed. Data were extracted by both authors according to predefined criteria and are summarised in narrative form.Four RCTs of C. racemosa as a treatment of menopausal symptoms were included. They yielded no compelling evidence for the efficacy of C. racemosa on menopausal symptoms. The small beneficial effects observed in some studies could be explained by a central activity, and an oestrogenic activity cannot be completely excluded.In spite of plausible mechanisms of action of C. racemosa, its clinical efficacy for the treatment of menopausal symptoms has not been convincingly demonstrated through rigorous clinical trials. Additional rigorous RCTs and biochemical and chemical investigations are warranted.