Wild yam, also known as Dioscorea villosa, is a perennial vine native to North America. It is distinct from the yams sold in U.S. grocery stores, although related to some of them. Health care practitioners have long found medicinal uses for wild yam's tubers or fleshy roots. Especially since the 1990s, popular controversy and confusion have arisen over whether wild yam works as a contraceptive. Do not try wild yam for any purpose without first consulting your physician.
Past and Present Medicinal Uses
“Cook's Physiomedical Dispensatory,” an 1869 reference on medicinal herbs, does not attribute contraceptive properties to wild yam, but does identify it as a“relaxant,” “antispasmodic,” and “excellent remedy” for “painful menstruation" ... "vomiting during gestation” and uterine pain of late pregnancy. Early 21st century herbalists such as Sharol Tilgner, Henriette Kress and Paul Bergner note some of the same possible uses for wild yam, but again do not present it as a potential contraceptive. The same is true of some conventional medical websites such as MedlinePlus and Drugs.com.
Wild yam contains 0.5 to 1.2 percent diosgenin, its “active ingredient.” Just like many human hormones, including those regulating the female reproductive system, diosgenin belongs to a group of chemicals called steroids. During the 1940s, chemist Russell Marker isolated diosgenin from a related plant, Mexican wild yam, Dioscorea mexicana. He invented an industrial-scale conversion of this compound into the female reproductive hormone progesterone. Diosgenin from this species was later used to manufacture synthetic adrenal gland hormones and testosterone, as well as the progesterone and estrogen in hormonal contraceptives. Since the 1970s, soybean and lanolin extracts have largely replaced yam-derived diosgenin in hormone synthesis because it has become too expensive, according to the website Henriette’s Herbal.
The possible hormonal effects of diosgenin itself in the human body have not been entirely ruled out. At the same time, there is no scientific evidence that the human body can convert diosgenin extracted from any Dioscorea species into any steroid hormone, including progesterone. This conversion only takes place in the laboratory. Thus it is highly improbable that wild yam or its active compound could function as herbal versions of contraceptive pills. The historical use of yam-extracted diosgenin in the making of the pill has led to confusion and misinformation over whether wild yam species can function as birth control, according to Henriette’s Herbal.
Alternatives to Synthetic Hormonal Contraception
To prevent unintended pregnancy without putting synthetic hormones into your body or urinating them into the environment, use other birth control methods whose effectiveness is well-established. These include sexual practices that do not carry the risk of conception; natural family planning/fertility awareness; barrier methods such as the male condom, female condom or diaphragm plus spermicide; copper intrauterine devices; and male or female sterilization. Ask your health care provider about a good method -- or methods -- for you.