Red clover is no better than placebo for hot flushes

Question Is isoflavone from red clover effective in the treatment of perimenopausal hot flushes?

Synopsis Dietary supplements containing isoflavones derived from soy or red cloverare marketed as alternatives to hormone replacement therapy for menopausal women with hot flushes. A total of 252 women aged 45 to 60 years with at least 35 hot flushes per week and a follicle stimulating hormone > 30 mIU/ml were enrolled. Participants were randomised in a double blind fashion (concealed allocation assignment) to receive either Promensil (82 mg total isoflavones per day), Rimostil (57 mg total isoflavones per day), or identical placebo. Both supplements were derived from red clover. A total of 246 patients (98%) were followed up for a total of 12 weeks. Individuals assessing outcomes were blinded to treatment group assignment. Data were analysed according to both intention to treat and per protocol (meaning that only compliant patients who took their medications were included in the analysis). Reductions in mean daily hot flush counts were equal among the three groups: a mean of 8.1 per day at baseline decreased to 5.0 per day after treatment. Per protocol results were similar to the intention to treat analyses (meaning that the supplements were ineffective in the women who consistently used them). No significant adverse events were reported in any of the groups.

Bottom line Isoflavone derived from red clover is no more effective than placebo in treating menopausal hot flushes, although both worked for many women. Results have also been mixed for soy based products. We still need more options for the problem of hot flushes.

Level of evidence 1b (see www.infopoems.com/resources/levels.html); individual randomised controlled trials (with narrow confidence interval).

Tice JA, Ettinger B, Ensrud K, et al. Phytoestrogen supplements for the treatment of hot flashes: The isoflavone clover extract (ICE) study. A randomized controlled trial.JAMA 2003;290: 207-14.

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