Knotweed, particularly Polygonum cuspidatum (Japanese knotweed), is used in traditional medicine systems such as Traditional Chinese Medicine (TCM) for a variety of conditions, including those related to aging and women's health. Its use for menopause is primarily based on tradition rather than robust scientific validation. Knotweed contains several active compounds, notably resveratrol, which has antioxidant properties and is speculated to offer some benefits for symptoms commonly experienced during menopause, such as hot flashes or mood changes. However, while there is some preclinical research suggesting that resveratrol might affect estrogen receptors or mitigate oxidative stress (which can be relevant to menopausal symptoms), there is a lack of high-quality human clinical trials specifically evaluating knotweed or its extracts for menopause management.

Most of the support for knotweed in menopause comes from its historical use as a tonic and adaptogen in Asian herbal medicine, rather than from direct evidence. Some modern herbal formulas for menopause include knotweed among other botanicals, but again, the evidence is mostly anecdotal or extrapolated from its general antioxidant effects. Therefore, while knotweed may be traditionally used for menopausal symptoms, current scientific evidence to justify its effectiveness in this context is limited.