Phytoestrogens are plant-derived compounds structurally similar to the hormone estrogen. They are found in foods such as soybeans, flaxseeds, and whole grains. Their use to support the vaginal body system, particularly for managing symptoms of vaginal atrophy and dryness during menopause, is supported by a moderate amount of scientific evidence. Phytoestrogens can bind to estrogen receptors and exert weak estrogenic or anti-estrogenic effects depending on endogenous estrogen levels.

Several clinical studies and meta-analyses have examined the effects of phytoestrogens (especially isoflavones from soy) on vaginal health in postmenopausal women. Some research suggests that phytoestrogen supplementation can improve vaginal epithelial maturation, increase lubrication, and reduce symptoms such as dryness and discomfort. However, results are mixed; while some studies show significant benefits, others find little to no improvement compared to placebo.

Systematic reviews (such as those published in Menopause and Climacteric) conclude that phytoestrogens may offer mild to moderate relief for vaginal atrophy and related symptoms, but are generally less effective than prescription estrogen therapies. Safety profiles are favorable, which makes phytoestrogens an option for women who cannot or do not wish to use hormone replacement therapy. Overall, the evidence justifies their use for vaginal support, though with moderate efficacy.