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...
- Menopausal symptoms. Applying wild yam cream to the skin for 3 months does not seem to relieve menopausal symptoms such as hot flashes and night sweats. It also does not seem to affect levels of hormones such as follicle stimulating hormone (FSH), estradiol, or progesterone, which 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.
- Menstrual disorders.
- Other conditions.
More evidence is needed to rate the effectiveness of wild yam for these uses.
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.
Wild yam is POSSIBLY SAFE when taken by mouth or applied to the skin. Large amounts can cause vomiting.
Special precautions & warnings:
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.
Be cautious with this combination.
Wild yam might have some of the same effects as estrogen. Taking wild yam along with estrogen pills might decrease the effects of estrogen pills.
Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.
There are no known interactions with herbs and supplements.
There are no known interactions with foods.
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.
American Yam, Atlantic Yam, Barbasco, China Root, Chiense Yam, Colic Root, Devil's Bones, DHEA Naturelle, Dioscorea, Dioscoreae, Dioscorea alata, Dioscorea batatas, Dioscorea composita, Dioscorea floribunda, Dioscorea hirticaulis, Dioscorea japonica, Dioscorea macrostachya, Dioscorea mexicana, Dioscorea opposita, Dioscorea tepinapensis, Dioscorea villosa, Dioscorée, Igname Sauvage, Igname Velue, Mexican Yam, Mexican Wild Yam, Ñame Silvestre, Natural DHEA, Phytoestrogen, Phyto-œstrogène, Rheumatism Root, Rhizoma Dioscorae, Rhizoma Dioscoreae, Shan Yao, Wild Mexican Yam, Yam, Yuma.
To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (http://www.nlm.nih.gov/medlineplus/druginfo/natural/methodology.html).
To see all references for the Wild yam page, please go to http://www.nlm.nih.gov/medlineplus/druginfo/natural/970.html.
- Rosenberg Zand, R. S., Jenkins, D. J., and Diamandis, E. P. Effects of natural products and nutraceuticals on steroid hormone-regulated gene expression. Clin Chim.Acta 2001;312(1-2):213-219. View abstract.
- Wu WH, Liu LY, Chung CJ, et al. Estrogenic effect of yam ingestion in healthy postmenopausal women. J Am Coll Nutr 2005;24:235-43. View abstract.
- Cheong JL, Bucknall R. Retinal vein thrombosis associated with a herbal phytoestrogen preparation in a susceptible patient. Postgrad Med J 2005;81:266-7.. View abstract.
- Komesaroff PA, Black CV, Cable V, et al. Effects of wild yam extract on menopausal symptoms, lipids and sex hormones in healthy menopausal women. Climacteric 2001;4:144-50.. View abstract.
- Eagon PK, Elm MS, Hunter DS, et al. Medicinal herbs: modulation of estrogen action. Era of Hope Mtg, Dept Defense; Breast Cancer Res Prog, Atlanta, GA 2000;Jun 8-11.
- Yamada T, Hoshino M, Hayakawa T, et al. Dietary diosgenin attenuates subacute intestinal inflammation associated with indomethacin in rats. Am J Physiol 1997;273:G355-64. View abstract.
- Aradhana AR, Rao AS, Kale RK. Diosgenin-a growth stimulator of mammary gland of ovariectomized mouse. Indian J Exp Biol 1992;30:367-70. View abstract.
- Accatino L, Pizarro M, Solis N, Koenig CS. Effects of diosgenin, a plant-derived steroid, on bile secretion and hepatocellular cholestasis induced by estrogens in the rat. Hepatology 1998;28:129-40. View abstract.
- Skolnick AA. Scientific verdict still out on DHEA. JAMA 1996;276:1365-7. View abstract.
- Foster S, Tyler VE. Tyler's Honest Herbal, 4th ed., Binghamton, NY: Haworth Herbal Press, 1999.
Last reviewed - 09/16/2014
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