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Wild yam's medicinal benefits have long been recognized by herbalists and pharmaceutical manufacturers alike. In the 18th and 19th centuries, this herb was used to treat menstrual cramps and problems related to childbirth. The subsequent discovery of a substance contained in wild yams revolutionized the pharmaceutical industry. The tubers, or fleshy, rootlike parts, of wild yams (not to be confused with the sweet potato yam) contain diosgenin, a steroid-like substance that can be converted into the female hormone progesterone. Diosgenin has served a key role in the synthesis of hormones and the development of the birth control pill, two of the major advances in plant drug medicine this century. Wild yam continues to be used for treating menstrual cramps, and nausea and morning sickness associated with pregnancy, as well as inflammation, spasm, and other health conditions.

Plant Description

Wild yam (Dioscorea villosa) is native to Canada and the southern United States. It is one of an estimated 600 species of yam in the genus Dioscorea, many of them wild species that flourish in damp woodlands and thickets. Wild yam is a perennial, twining vine with pale brown, knotty, woody cylindrical rootstocks, or tubers. The rootstocks are crooked, and bear sideways branches of long creeping runners. The thin reddish-brown stems grow to a length of 5 to 12 meters. The roots initially taste starchy, but soon after taste bitter and acrid.

The wild yam plant has clusters of small, drooping green-white to green-yellow flowers. The heart-shaped leaves are long and broad and long-stemmed, with prominent veins. The upper surface of the leaves is smooth while the underside is downy.

Parts Used

The dried rhizome with roots are used in commercial preparations.

Medicinal Uses/Indications

Wild yam is used to treat the following conditions and symptoms.

bulletMenstrual cramps
bulletIntestinal colic
bulletRheumatoid arthritis
bulletGallbladder colic

This plant also produces sweat and stimulates the flow of bile to the duodenum, a part of the small intestine.

Available Forms

Wild yam is available as liquid extract and powdered tuber products.

How to Take It

The following are recommended doses for wild yam.

bulletDried herb: 1 to 2 tsp. three times a day
bulletTincture: 2 to 4 ml three times a day


Overdosing can be potentially poisonous because a substance within wild yam can be toxic.

Possible Interactions

No harmful drug interactions have been reported.

Supporting Research

Aikman L. Nature's Healing Arts: From Folk Medicine to Modern Drugs. Washington, DC: National Geographic Society; 1977:186-189, 196.

Arvigo R, Balick M. Rainforest Remedies: One Hundred Healing Herbs of Belize. Twin Lakes, Wis: Lotus Press; 1993: 194-195.

British Herbal Pharmacopoeia. 4th ed. Great Britain: Biddles Ltd, Guildford and King's Lynn; 1996:187.

Dorland's Illustrated Medical Dictionary. 25th ed. Philadelphia, Pa: W.B. Saunders; 1974.

Duke JA. The Green Pharmacy. New York, NY: St Martin's Press; 1997:111, 209-210, 352

Duke JA. Phytochemical Database, USDA–ARS–NGRL, Beltsville Agricultural Research Center, Md. Available at:

Duke J, Vasquez R. Amazonian Ethnobotanical Dictionary. Boca Raton, Fla: CRC Press; 1994:66-67.

Etkin N, ed. Plants in Indigenous Medicine and Diet: Biobehavioral Approaches. Bedford Hills, NY: Redgrave Publishing; 1986: 131-150.

Grieve M. A Modern Herbal. Vol. II. New York, NY: Dover; 1971:863.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company; 1998:809-810.

Mabberley DJ. The Plant-Book: A Portable Dictionary of the Higher Plants. England: Cambridge University Press; 1987: 185


Thomson WA, ed. Medicines from the Earth: A Guide to Healing Plants. Maidenhead, England: McGraw-Hill Book Company; 1978:61.

Vasiukova N, Paseshnichenko V, Davydova M, Chalenko G. Pharmacological evaluation of Dioscorea dumetorum tuber used in traditional antidiabetic therapy. J Ethnopharmacol. 1986;15(ISS 2):133-144.

Copyright © 2000 Integrative Medicine Communications

The publisher does not accept any responsibility for the accuracy of the information or the consequences arising from the application, use, or misuse of any of the information contained herein, including any injury and/or damage to any person or property as a matter of product liability, negligence, or otherwise. No warranty, expressed or implied, is made in regard to the contents of this material. No claims or endorsements are made for any drugs or compounds currently marketed or in investigative use. This material is not intended as a guide to self-medication. The reader is advised to discuss the information provided here with a doctor, pharmacist, nurse, or other authorized healthcare practitioner and to check product information (including package inserts) regarding dosage, precautions, warnings, interactions, and contraindications before administering any drug, herb, or supplement discussed herein.