Dioscorea oppositifolia, commonly known as Chinese yam or "nagaimo," has a long history of use in traditional Chinese medicine (TCM). In TCM, it is valued for its role in nourishing the spleen, stomach, and kidneys, and is sometimes included in herbal formulas for female reproductive health, including amenorrhea (absence of menstruation). The rationale in traditional practice is based on the belief that amenorrhea may be caused by deficiencies in "qi" or "yin," for which Dioscorea oppositifolia is thought to provide support due to its tonifying properties.

However, there is little to no robust scientific evidence to directly support the use of Dioscorea oppositifolia for treating amenorrhea. Most available studies focus on its general health benefits, such as antioxidant properties, effects on blood sugar regulation, and gastrointestinal health. The use of Dioscorea (often misattributed to Dioscorea villosa or wild yam) as a phytoestrogen has been speculated, but research has not demonstrated significant estrogenic effects or direct impact on menstrual cycles in humans.

In summary, the use of Dioscorea oppositifolia for amenorrhea is primarily justified by historical and traditional practice rather than scientific validation. Evidence supporting its efficacy for this specific condition is weak, and modern clinical trials are lacking.