Vasomotor symptom relief by soy isoflavone extract tablets in postmenopausal women: a multicenter, double-blind, randomized, placebo-controlled study

Author: Upmalis DH et al.

Publication: Menopause. 2000 Jul-Aug;7(4):236-42.

Soybean products and isoflavones supplements are widely used to relief menopausal symptoms. This study was carried out with 177 post-menopausal woman, with mean age of 55 years. The test was double-blind and randomized. Before the test the postmenopausal woman were having daily five or more hot flushes, the most important menopausal symptom. The woman were randomized to receive either 50 mg soy isoflavones (genistin and daidzin per day) or placebo. At the start and end of the study physical examinations and endometrial and biochemical tests were performed.

After 2 weeks a decreases in the incidence and severity of hot flushes was observed in the group who took soy isoflavones. Over a period of 12 weeks the differences between the two groups approached significance (p = 0.08). There was no changed observed in the endometrial thickness, lipoproteins, bone markers, sex hormone-binding globulin and follicle-stimulating hormone and vaginal cytology.

It was concluded that soy isoflavones was effective in reducing frequency and severity of flushes but did not stimulate the endometrium in menopausal women.