A natural oral contraceptive

Wild yam or dioscorea villosa contains diosgenin, a glycoside that can easily be converted to the hormone progesterone. In a study carried out over a four year period Wild yam was found to be effective as an oral contraceptive, but without the side effects of the pill.

What is it?

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 effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for WILD YAM are as follows:

Possibly ineffective for...

• Hot flashes and night sweats associated with menopause, when wild yam cream is applied to the skin. Using wild yam cream for 3 months doesn’t seem to help with these menopausal symptoms. It also doesn’t seem to affect levels of hormones such as follicle stimulating hormone (FSH), estradiol, or progesterone that play a role in menopause.

Insufficient evidence to rate effectiveness for...

• 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.
• Other conditions.

More evidence is needed to rate wild yam for these uses.