Wild yam (Dioscorea villosa) was used for pain relief by the Aztecs and Mayans, and later called colic root in the United States when used for pain and gastrointestinal upset. It became popular for menopausal symptoms due to the misconception it is a natural hormone. Although wild yam is the source of diosgenin – the raw material used to produce the sex hormone progesterone in the laboratory – it does not contain or convert to progesterone in humans.
Wild yam is mainly used as a vaginal cream made out of dried root extract. It can also be taken orally or as a supplement.
Wild yam contains a chemical that can be made into hormones such as estrogen and dehydroepiandrosterone (DHEA) in the laboratory. However there is no evidence the body can convert the constituents of wild yam into these hormones.
There is little reliable evidence that wild yam extract works and no clinical or scientific research supporting its use for menopausal symptoms. An Australian trial found it appeared free of side effects, but appeared to have little effect on menopausal symptoms including hot flushes and night sweats. A review of treatments for hot flushes found insufficient data to prove effectiveness of wild yam.