The effect of isoflavone on vaginal dryness and dyspareunia in postmenopausal symptoms: a systematic review and meta-analysis.

Vaginal dryness and dyspareunia are frequent complaints among postmenopausal women. Studies have shown that isoflavones reduce the severity of menopausal symptoms. This study aimed to evaluate the effects of isoflavones on vaginal dryness and dyspareunia in postmenopausal women. PubMed, ScienceDirect, and Cochrane Library electronic databases were searched until June 15, 2024. Revman 5.4 software (The Nordic Cochrane Centre, Copenhagen, Denmark) was used to analyze the data. Ten randomized controlled trials (RCTs), totaling 675 participants, were included in the isoflavone treatment, and the duration was between 4 and 48 weeks. For the meta-analysis, four and two RCTs were conducted to analyze vaginal dryness and dyspareunia in postmenopausal women before and after isoflavone treatment, respectively. The analysis results for vaginal dryness showed a significant change after isoflavone therapy, whereas those for dyspareunia did not show a significant change. The random-effects estimation of the mean difference was -1.29, and 95% confidence interval (CI) was -2.53 to -0.04 (p=0.04) for vaginal dryness, and -0.82, with a 95% CI of -3.51 to 1.87 (p=0.55) for dyspareunia. This meta-analysis concluded that isoflavones have a significant effect on relieving vaginal dryness but have no impact on dyspareunia in postmenopausal women. Numerous larger, long-term trials are needed to fully assess their effects and efficacy.