Wild Yam (Dioscorea villosa)

Wild yam is a plant. It contains a chemical, diosgenin, which can be made in the laboratory into various steroids, such as estrogen and dehydroepiandrosterone (DHEA). The root and the bulb of the plant are used as a source of diosgenin, which is prepared as an “extract,” a liquid that contains concentrated diosgenin.

There are over 600 species of wild yam. Some species are grown specifically as a source of diosgenin for laboratories to use in making steroids. These species are generally not eaten due to a bitter flavor. Only about 12 of the 600 species are considered edible.

Diosgenin or wild yam is often promoted as a “natural alterative” to estrogen therapy, so you will see it used for estrogen replacement therapy, vaginal dryness in older women, PMS (premenstrual syndrome), menstrual cramps, weak bones (osteoporosis), increasing energy and sexual drive in men and women, and breast enlargement. Wild yam does seem to have some estrogen-like activity, but it is not actually converted into estrogen in the body. It takes a laboratory to do that.

Similarly, you will also see wild yam and diosgenin promoted as a “natural DHEA.” This is because in the laboratory DHEA is made from diosgenin, but this chemical reaction is not believed to occur in the human body. So taking wild yam extract will not increase DHEA levels in people. Individuals who are interested in taking DHEA should avoid wild yam products labeled as "natural DHEA."

Wild yam is also used for treating a disorder of the intestines called diverticulosis, gallbladder pain, rheumatoid arthritis, and for increasing energy.

Some women apply wild yam creams to the skin to reduce menopausal symptoms such as hot flashes.

How does it work?

Wild yam contains a chemical that can be made into various steroids, such as estrogen, in the laboratory. However, the body can't change wild yam to estrogen.

Use as a natural alternative to estrogens.
Postmenopausal vaginal dryness.
PMS (Premenstrual syndrome).
Weak bones (osteoporosis).
Increasing energy and sexual desire in men and women.
Gallbladder problems.
Painful menstrual periods.
Rheumatoid arthritis.
Infertility.
Menstrual disorders.

The appropriate dose of wild yam depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for wild yam. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Wild yam is SAFE when taken by mouth or applied to the skin. Large amounts can cause vomiting.

Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking wild yam if you are pregnant or breast feeding. Stay on the safe side and avoid use.

Hormone-sensitive condition such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Wild yam might act like estrogen. If you have any condition that might be made worse by exposure to estrogen, do not use wild yam.

Protein S deficiency: People with protein S deficiency have an increased risk of forming clots. There is some concern that wild yam might increase the risk of clot formation in these people because it might act like estrogen. There is one case report of a patient with protein S deficiency and systemic lupus erythematosus (SLE) who developed a clot in the vein serving the retina in her eye 3 days after taking a combination product containing wild yam, dong quai, red clover, and black cohosh. If you have protein S deficiency, it is best to avoid using wild yam until more is known.