Wild yam in Avicenna contains a compound called diosgenin that mimics estrogen and progesterone in animals. Diosgenin can be converted into active steroid compounds in the lab.
Studies in humans are quite limited. Data show mixed results on menopausal symptoms in a few small studies that use different species and formulas of wild yam extract. Another small study suggests that increasing yam intake through diet may improve sex hormone and cholesterol levels.
A lab study showed that wild yam extract has weak hormonal activity against human breast cancer cells, but this does not mean it can prevent or treat cancer.
More studies are needed to confirm whether wild yam or its extract actually has any benefits. Because wild yam has estrogenic effects, patients with hormone-sensitive cancers should talk to their physicians before consumption.