Because soy isoflavones have a structure similar to estrogen, they can bind to estrogen receptors and have similar effects. A meta-analysis suggested that adding soy foods to the diet reduced the frequency of hot flushes in postmenopausal women.[1] Soy isoflavones may also help mitigate the increased risk of cardiovascular disease that is associated with menopause.[2][3] Soy isoflavones had similar effects on hot flushes and vaginal dryness as hormone-replacement therapy (HRT) but did not improve the overall menopause rating scale (MRS).[4][5] Another study that used self-reporting of the MRS found some improvement in sleep disturbances as well.[6] This suggests that soy isoflavones did not improve many of the other symptoms of menopause that HRT can improve, such as anxiety, irritability, depression, exhaustion, and joint pain.[4][5]
Although several studies support the use of soy isoflavones as a treatment for the symptoms of menopause, there is high heterogeneity between these studies, likely due to a variety of study designs, dosages studied, and reported outcomes. Because of this, they are not yet recommended as a stand-alone treatment option for menopause symptoms.