In the 18th and 19th centuries, wild yam (Dioscorea villosa) was used
by herbalists 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, root-like parts, of wild yams
(not to be confused with the sweet potato yam) contain diosgenin, a steroid-like
substance that is involved in the production of the hormone progesterone.
Diosgenin has served a key role in the making 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, nausea and
morning sickness associated with pregnancy, inflammation, osteoporosis,
menopausal symptoms, and other health conditions.
Also known as colic root, wild yam is a twining, tuberous vine native to
North America. 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
horizontal branches of long creeping runners. The thin reddish-brown stems grow
to a length of over 30 feet. The roots initially taste starchy, but soon after
taste bitter and acrid.
The wild yam plant has clusters of small, drooping greenish-white and
greenish-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.
The dried root, or rhizome, is used in commercial
Medicinal Uses and Indications
General Early Americans used wild yam to treat colic; hence,
the term colic root. Traditionally, it has been used to treat inflammation,
muscle spasms and a range of disorders including asthma. Related species of
Dioscorea are used in the Amazon and in central America to treat conditions
including fever, urinary tract infections, colds, rheumatism (joint and muscle
related conditions), arthritis, hemorrhoids, boils, and dysentery.
Menopause and Osteoporosis While the diosgenin found in wild
yam created quite a stir in the 1990s as a cure for menopausal disorders and
other symptoms of aging in women, the plant itself has no proven hormonal
action, nor have any studies shown it to be effective in treating hormone
related disorders. It is true that diosgenin can be converted into steroidal
compounds, which are then used in the chemical synthesis of progesterone, but
this is in the laboratory—not in the human body. There
is essentially no scientific evidence of wild yam's effectiveness in treating
menopausal symptoms or osteoporosis. Although many individuals claim relief of
symptoms such as vaginal dryness with the use of progesterone creams, some of
which contain an extract of Dioscorea villosa, no well-designed studies
have evaluated these creams. Moreover, many products that claim to contain
natural progesterone actually contain synthetic medroxyprogesterone acetate
Available Forms Wild yam is available as liquid extract and
powdered tuber products. The powdered form may be purchased in capsules or
compressed tablets. The fluid extract can be made into tea.
How to Take It
It is unclear whether wild yam is safe in children; therefore, use should be
specifically directed by a knowledgeable healthcare practitioner and limited to
The following are recommended adult doses for wild yam:
Dried herb to make tea: 1 to 2 tsp dried root to 1 cup water. Pour
boiling water over dried root, steep 3 to 5 minutes. Drink three times a day
Tincture: 40 to 120 drops, three times a day
Fluid extract: 10 to 40 drops, three to four times per day
The use of herbs is a time-honored approach to strengthening the body and
treating disease. Herbs, however, contain active substances that can trigger
side effects and interact with other herbs, supplements, or medications. For
these reasons, herbs should be taken with care, under the supervision of a
practitioner knowledgeable in the field of botanical medicine. Because wild yam
contains dioscorin, a substance that can be toxic, it is particularly important
to stay within the recommended dosages.
If you are currently being treated with any of the following medications, you
should not use wild yam without first talking to your healthcare provider.
Estradiol An animal study indicated that the active component
of wild yam, diosgenin, may interact with estradiol, a hormone that occurs
naturally in the body and that is also used in some birth control medications
and certain hormone replacement therapies.
Accatino L, Pizarro M, Solis N, Koenig C. Effects of diosgenin, a plant
derived steroid, on bile secretion and hepatocellular cholestasis induced by
estrogens in the rat. Hepatology. 1998;28(1):129-140.
Bone K, Mill S, eds. Principles and Practices of Phytotherapy, Modern
Herbal Medicine. London: Churchill Livingstone; 2000.
British Herbal Pharmacopoeia. 4th ed. Great Britain: Biddles Ltd,
Guildford and King's Lynn; 1996:187.
Duke JA. Phytochemical Database,
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Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines.
2nd ed. Montvale, NJ: Medical Economics Company; 2000:817-818.
Komesaroff PA, Black CV, Cable V, Sudhir K. Effects of wild yam extract on
menopausal symptoms, lipids and sex hormones in healthy menopausal women.
Robbers JE, Tyler VE. Tyler's Herbs of Choice: The Therapeutic Use of
Phytomedicinals. New York, NY: The Haworth Herbal Press;1999:187-188.
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Review Date: April 2002
Reviewed By: Participants in the review process include: Jacqueline A. Hart, MD,
Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University
and Senior Medical Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh
(Pediatric Dosing section February 2001), Johnson Drugs, Natick, MA; Steven
Ottariono, RPh (Pediatric Dosing section February 2001), Veteran's
Administrative Hospital, Londonderry, NH; R. Lynn Shumake, PD, Director,
Alternative Medicine Apothecary, Blue Mountain Apothecary & Healing Arts,
University of Maryland Medical Center, Glenwood, MD; David Winston, Herbalist
(September 1999), Herbalist and Alchemist, Inc., Washington, NJ. All interaction
sections have also been reviewed by a team of experts including Joseph Lamb, MD
(July 2000), The Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh
(August 2000), Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in
Pharmacy (March 2000), Clinical Assistant Professor, University of Maryland
School of Pharmacy; President, Your Prescription for Health, Owings Mills, MD;
Ira Zunin, MD, MPH, MBA (July 2000), President and Chairman, Hawaii State
Consortium for Integrative Medicine, Honolulu,
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