Isoflavones from red clover (Promensil) significantly reduce menopausal hot flush symptoms compared with placebo.

Objectives: To investigate the effectiveness and safety of a red clover isoflavone dietary supplement (Promensil, Novogen Ltd., Australia) versus placebo on the change in hot flush frequency in postmenopausal women.

Methods: In this randomized, double blind, placebo-controlled trial 30 women with more than 12 months amenorrhoea and experiencing more than five flushes per day were enrolled. All received single blind placebo tablets for 4 weeks and were subsequently randomized to either placebo or 80 mg isoflavones for a further 12 weeks. Efficacy was measured by the decrease in number of hot flushes per day and changes in Greene Climacteric Scale Score.

Results: During the first 4 weeks of placebo the frequency of hot flushes decreased by 16%. During the subsequent double blind phase, a further, statistically significant decrease of 44% was seen in isoflavones group (P<0.01), whereas no further reduction occurred within the placebo group. The Greene score decreased in the active group by 13% and remained unchanged in the placebo group.

Conclusion: In this study, treatment with 80 mg isoflavones (Promensil) per day resulted in a significant reduction in hot flushes from baseline. At the end of the study there was a significant decrease in hot flushes of 44% between the active and placebo group, demonstrating the effectiveness of Promensil in the management of hot flushes.