Botanical name: Dioscorea villosa
© Steven Foster
Parts used and where grown
Wild yam plants are found across the midwestern and eastern United States, Latin America
(especially Mexico), and Asia. Several different species exist. All of which possess similar
constituents and properties. The root is used medicinally.
Wild yam has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
Historical or traditional use (may
or may not be supported by scientific studies)
Wild yam has been used by herbalists as an expectorant for people with coughs. It was also used for gastrointestinal upset, nerve pain, and morning sickness.1 Eventually, it was
discovered that the saponins from wild yam could be converted industrially into cortisone, estrogens, and progesterone-like compounds. Wild yam and other plants
with similar constituents continue to be a source for these drugs.
Active constituents
The steroidal saponins (such as diosgenin) account for some of the activity of wild yam.
Another compound, dioscoretine, has been shown in animal studies to lower blood sugar
levels.2 An extract of wild yam was also found in a clinical trial to have antioxidant properties and raised HDL, the
“good,”cholesterol in elderly
adults.3
Contrary to popular claims, wild yam roots do not contain and are not converted into progesterone or dehydroepiandrosterone (DHEA) in the body.4 5
Pharmaceutical progesterone is made from wild yam using a chemical conversion process. This
can lead to confusion—while wild yam can be a source of progesterone, it cannot be used
without this pharmaceutical conversion, which cannot be duplicated by the body. Women who
require progesterone should consult with their physician and not rely on wild yam
supplements.
How much is usually taken?
Up to 2–3 ml of wild yam tincture can be taken three to four times per day.
Alternatively, 1 gram of dried, powdered root can be taken three times each
day.6
Are there any side effects or interactions?
Some people may experience nausea or vomiting when taking large amounts of wild yam
(several times the amounts listed above). The safety of wild yam during pregnancy and breast feeding has not been
established.
At the time of writing, there were no well-known drug interactions
with wild yam.
References:1. Lust JB. The Herb Book. New York: Bantam Books, 1974,
401.
2. Iwu MM, Okunji CO, Ohiaeri GO, et al. Hypoglycaemic activity of
dioscoretine from tubers of Dioscorea dumetorum in normal and alloxan diabetic
rabbits. Planta Med 1990;56:264–7.
3. Araghiniknam M, Chung S, Nelson-White T, et al. Antioxidant activity
of dioscorea and dehydroepiandrosterone (DHEA) in older humans. Life Sci
1996;11:147–57.
4. Araghiniknam M, Chung S, Nelson-White T, et al. Antioxidant activity
of dioscorea and dehydroepiandrosterone (DHEA) in older humans. Life Sci
1996;11:147–57.
5. Dollbaum CM. Lab analyses of salivary DHEA and progesterone following
ingestion of yam-containing products. Townsend Letter for Doctors and Patients Oct
1995:104.
6. Bertram T. Encyclopedia of Herbal Medicine. Dorset, England:
Grace Publishers, 1995, 454.