Wild Yam
DioscoreaceaeDioscorea villosa
Also known as: Colic Root, Rheumatism Root, Devil Bones
clinical_notes Clinical Summary
Wild Yam (Dioscorea villosa) is a North American twining vine whose rhizome contains diosgenin and steroidal saponins.
Historically valued as an antispasmodic for uterine and biliary colic, it remains widely used in women health protocols for dysmenorrhea and menopausal support, though clinical evidence for hormonal effects is limited.
The key distinction is that diosgenin cannot be converted to progesterone in the human body (laboratory chemistry is required), making topical cream claims largely unsupported.
The antispasmodic and anti-inflammatory actions on smooth muscle have traditional validation but require further clinical trials.
Pregnancy Safety
Small amounts have traditional use for dysmenorrhea and uterine spasm; midwives occasionally use it for morning sickness. Large doses should be avoided. No clinical trials in pregnancy. Use only under supervision of qualified herbalist.
Lactation Safety
Insufficient clinical data. Phytoestrogenic activity is theoretical concern. Avoid high doses during lactation; food amounts of Dioscorea species are generally considered safe.
warning Contraindications
- Hormone-sensitive cancers (breast, ovarian, uterine, prostate) (avoid)Theoretical
- Pregnancy (large doses) (caution)Theoretical
- Protein S deficiency or haemophilia (contraindicated)Theoretical
vital_signs Clinical Profile
Primary Indications
- check_circle dysmenorrhea
- check_circle uterine spasm
- check_circle biliary colic
- check_circle IBS
- check_circle menopausal support
- check_circle rheumatoid arthritis
- check_circle ovarian pain
- check_circle nausea of pregnancy
- check_circle muscle cramps
Therapeutic Actions
System Affinities
- check_circle reproductive (female)
- check_circle digestive
- check_circle musculoskeletal
- check_circle hepatic
labs Active Constituents
diosgenin
dioscin
gracillin
dioscorin
methyl parvifloside
protodeltonin
starch
tannins
phytosterols
allantoin
history_edu Traditional Use
Traditional Chinese Medicine (TCM)
山药 (Shan Yao)
Nature: neutral
- Spleen Qi and Yin deficiency
- Lung deficiency cough
- Kidney deficiency with spermatorrhea
- Leucorrhoea from Spleen deficiency
- Diabetes (Xiao Ke)
Note: In TCM, Shan Yao typically refers to Dioscorea oppositifolia (Chinese yam) rather than D. villosa (Wild Yam). The Western and TCM herbs share the genus but differ in species. The TCM properties listed are for D. oppositifolia; D. villosa is used primarily in Western herbal medicine.
Traditional Uses Across Healing Systems
While many herbs lack controlled clinical trials, centuries of traditional practice across cultures provide valuable insight into their therapeutic applications.
Used by Native American peoples (Cherokee, Mahican) for rheumatism, biliary colic, and as an antispasmodic for digestive and uterine conditions
The Eclectic medical movement in the 19th century popularized wild yam as colic root, prescribing it for biliary colic, nausea, and uterine cramps.
Antispasmodic for uterine cramping, dysmenorrhea, biliary colic, bowel spasm, and rheumatoid arthritis
Wild yam root became industrially important in the 1940s as the primary source of diosgenin for synthesis of the first oral contraceptive pill. This history fuels modern marketing claims about hormonal effects that are not supported by clinical evidence for the whole herb.
Closely related species (D. alata, D. bulbifera) used for strength-building, aphrodisiac, and digestive support
Indian wild yam species used in Rasayana (rejuvenative) formulations; D. villosa itself is not an Ayurvedic herb but the genus is well-represented.
spa Parts Used
root
- antispasmodic for uterine and biliary colic
- anti-inflammatory for arthritis
- hormonal support
- dysmenorrhea
Dried rhizome used as decoction, tincture (1:5, 40%), or capsule. Cream preparations of wild yam extract do not convert to progesterone in the body; conversion requires laboratory chemistry.
shield Safety
Contraindications — Evidence Basis
Hormone-sensitive cancers (breast, ovarian, uterine, prostate)
Diosgenin has estrogenic and progestogenic activity in vitro. Avoid in estrogen receptor-positive or progesterone receptor-positive cancers.
Pregnancy (large doses)
Small amounts traditionally used by midwives for uterine spasm and nausea; however, large doses should be avoided given lack of safety data. Use only under qualified supervision.
Protein S deficiency or haemophilia
Diosgenin may affect coagulation pathways. Contraindicated in bleeding disorders.
Toxicity
Significant adverse effects not well documented at normal therapeutic doses; high doses may cause nausea, vomiting, diarrhea
Nausea, vomiting, diarrhea at excessive doses; potential chronic kidney injury with very high doses (animal data)
Discontinue. Supportive care. Monitor renal function with prolonged high-dose use.
Adverse Effects
CYP Metabolism
Limited CYP data available. Diosgenin and dioscin are metabolized hepatically. No significant CYP interactions currently documented.
swap_horiz Interactions
Estrogen Therapy / Hormone Replacement Therapy (Conjugated Estrogens, Estradiol)
Class: Hormone Therapy
Wild yam contains diosgenin, a steroidal saponin with weak estrogenic activity in vitro that may bind to estrogen receptors. Competitive receptor binding may partially antagonize the effects of exogenous estrogen preparations. However, the human body cannot convert diosgenin to progesterone or estrogen, so effects are weaker than often claimed.
Women using HRT should be cautious with high-dose wild yam products, as estrogenic effects may compete with pharmaceutical estrogens. Patients with hormone-sensitive conditions (breast cancer, endometriosis, uterine fibroids) should avoid wild yam. Consult physician before use.
Oral Contraceptives (Combined Oral Contraceptives, Progestogen-Only Pills)
Class: Oral Contraceptives
Wild yam's weak phytoestrogenic activity via diosgenin may compete with ethinyl estradiol at receptor sites. This theoretical competition may reduce contraceptive efficacy. Additionally, hormonal fluctuations from regular wild yam use could theoretically interfere with OCP-mediated hormonal regulation.
Women taking oral contraceptives should use caution with high-dose wild yam supplements. Advise use of backup contraception if taking therapeutic wild yam doses. Culinary yam consumption is not likely to cause interaction.
Tamoxifen / Selective Estrogen Receptor Modulators (SERMs)
Class: Antineoplastic / SERM
Wild yam's diosgenin has demonstrated weak estrogenic activity against human breast cancer cells (MCF-7) in laboratory studies and may stimulate growth of mammary tissue. This could potentially antagonize the anti-estrogenic effects of tamoxifen used in hormone-sensitive breast cancer treatment.
Wild yam should be avoided in patients with estrogen receptor-positive cancers, especially those taking tamoxifen or other SERMs. Any use should be disclosed to the oncology team. The risk of tumor promotion with significant hormonal interference is a serious concern.
Antidiabetic Agents (Metformin, Insulin, Sulfonylureas)
Class: Antidiabetics
Dioscoretine, a compound in wild yam, has demonstrated blood sugar-lowering activity in animal studies by enhancing glucose uptake and insulin sensitivity. Concurrent use with antidiabetic medications may produce additive hypoglycemic effects.
Monitor blood glucose in diabetic patients using wild yam supplements regularly. Watch for symptoms of hypoglycemia, especially when taking insulin or sulfonylureas. The effect at standard supplement doses is likely mild.
Progesterone / Progestins (Medroxyprogesterone, Levonorgestrel, Norethindrone)
Class: Progestogens
Wild yam is often marketed as a 'natural progesterone' source, but diosgenin cannot be converted to progesterone in the human body without laboratory processing. Wild yam products that do not contain added synthetic progesterone are unlikely to meaningfully interact, but consumer confusion may lead to misuse. Products containing added progesterone could have additive effects.
Clarify whether the wild yam product contains added progesterone. Check product labels carefully. Patients who need progesterone therapy should use pharmaceutical preparations. Advise patients not to use wild yam as a substitute for prescribed progestogen therapy.
hub Combinations
Synergistic pairings can enhance therapeutic outcomes, while knowing suitable substitutes helps when specific herbs are unavailable or contraindicated.
No combination data available yet.
science Studies
Bioassay-guided evaluation of Dioscorea villosa - an acute and subchronic toxicity, antinociceptive and anti-inflammatory approach
In VivoThis in vivo study in rodents investigated the antinociceptive and anti-inflammatory activities of Dioscorea villosa dry extract, as well as its acute and subchronic toxicity profile. Oral administration of DV extract demonstrated significant dose-dependent antinociceptive effects in acetic acid-induced writhing and formalin-induced pain models. Anti-inflammatory activity was confirmed by reduction of carrageenan-induced leukocyte migration to the peritoneal cavity at doses of 100-400 mg/kg. No acute or subchronic toxicity was observed at tested doses, supporting a relatively safe profile for traditional anti-inflammatory applications.
Dioscorea villosa (wild yam) induces chronic kidney injury via pro-fibrotic pathways
In VivoThis in vivo safety study investigated the renal and hepatic effects of Dioscorea villosa extract administered orally to Sprague-Dawley rats at 0.79 g/kg/day for 7, 14, and 28 days. Histopathological analysis showed increased renal fibrosis markers including collagen deposition, vimentin, TGFbeta1, NFkappaB, and alpha-SMA by day 28. Liver inflammation was also observed at day 28. No acute reno- or hepatotoxicity was seen, but chronic exposure increased fibrosis markers. The authors recommend caution with long-term supplementation, particularly in individuals with pre-existing renal impairment or those co-administering nephrotoxic drugs.
medication Dosing
tincture
2-4 mL (1:5, 40% ethanol)
TID
Used for uterine and digestive antispasmodic effects. Best taken 30 min before meals or at onset of cramping.
capsule
250-500 mg dried root powder
2-3x/day
Standardized extracts based on diosgenin content (up to 6%) preferred for consistency. Topical cream preparations do not provide hormonal benefits without laboratory conversion.
Disclaimer: This information is largely AI-generated and reviewed by human experts at Evara Health. It is intended for educational and clinical reference purposes only and should not replace professional medical advice.
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