Euryale seed, also known as fox nut or "Qian Shi" in traditional Chinese medicine (TCM), has a long history of use in East Asian herbal practices. Within TCM, Euryale seed is commonly used to "tonify the spleen and stabilize the kidney," which, according to traditional theory, are thought to help regulate menstrual cycles and address menstrual irregularities. Practitioners believe that deficiencies or imbalances in the spleen and kidney can result in symptoms such as irregular menstruation, leucorrhea, and other reproductive concerns, and Euryale seed is often included in herbal formulas aimed at harmonizing these organ systems.

However, the scientific evidence supporting the use of Euryale seed specifically for menstrual irregularity is limited. Most available research focuses on its nutrient content, antioxidant properties, and potential effects on metabolic health rather than direct impacts on menstrual cycles. There are very few, if any, well-designed clinical studies evaluating its efficacy for menstrual irregularities in humans. As such, its use for this condition is justified primarily by tradition rather than by modern scientific validation. The rating of 2 reflects the strong traditional use but the lack of robust scientific evidence.