Wild Yam

Also known as: Dioscorea composita, barbasco, China root, yuma, colic root, devil's bones, rheumatism root.

Potential uses: Wild yam is a phytoestrogen. It's claimed that taking wild yam orally can relieve vaginal dryness and that wild yam cream can relieve hot flashes.

Usual dose: There is no typical dose.

Are there any risks? There are more than 500 species of wild yam. Some species contain diosgenin,which has a similar structure to dehydroepiandrosterone (DHEA). DHEA is a steroid that your body can turn into estrogen. Though DHEA has been sythnesized from wild yam extract in the lab, it's not clear if the human body can convert diosgenin into estrogen. Still, because diosgenin does have other estrogen-like properties, people diagnosed with hormone-receptor-positive breast cancer should not take wild yam.

What does the research say? In clinical studies, wild yam cream was no more beneficial than a placebo (regular hand cream) in controlling hot flashes. There is not enough research to determine whether wild yam reduces vaginal dryness.