Soy extract phytoestrogens with high dose of isoflavones for menopausal symptoms

The aim of the present study was to assess the efficacy and safety of a standardized compound based on an extract of soy phytoestrogens, with high doses of isoflavones in the management of menopausal hot flushes.

A total of 180 women aged 40-65 years with a minimum of five moderate-to-severe hot flushes in the last 7 days at baseline and absence of menstruation for at least 6 months participated in a 12-week prospective, randomized, double-blind, placebo-controlled multicenter trial. After a 2-week run-in period, women received one tablet a day of 80 mg isoflavones (corresponding to 60 mg of genistein) or a matching placebo.

The mean daily number of moderate-to-severe hot flushes decreased in both study groups, but the reduction was greater in the isoflavones arm at 6 (36.2%) and 12 weeks (41.2%) than in the placebo arm (24.0% at 6 weeks, 29.3% at 12 weeks), with a difference of 1.1 (95% CI [-2.0 to -0.06]) (P = 0.038) at 6 weeks and 1.1 (95% CI [-2.05 to -0.15]) (P = 0.023) at 12 weeks. Similar findings were obtained for hot flushes of any intensity. The Kupperman index decreased in both study groups. Relief of hot flushes was greater when time to menopause was >or=12 months and in cases of BMI >or=27 kg/m(2).

In daily practice conditions, high doses of isoflavones, particularly genistein, can be used for the management of hot flushes in postmenopausal women not treated with hormone replacement therapy due to their superior efficacy to placebo and very good safety profile.