wild yam

Wild yam refers to tuberous vines of Dioscorea species that commonly grow in damp woodlands. There are over 600 species of wild yams, out of which 12 are considered edible, and all others taste bitter. Some wild yams, including Dioscorea villosa and Dioscorea alata contain plant hormones (phytoestrogens) known as diosgenin, which is used as a raw material for the commercial production of synthetic estrogen and progesterone, female sex hormones, and dehydroepiandrosterone (DHEA), a precursor to male and female sex hormones.

Wild yam root extracts have been traditionally used as an herbal remedy for menopausal symptoms and many other ailments, however, there are no scientific studies to back any of wild yam’s purported therapeutic uses. Wild yam is promoted as a natural alternative to hormone therapy, however, wild yam itself does not contain estrogen or progesterone, and there is no evidence that the body can convert diosgenin into progesterone or other hormones. Diosgenin has to undergo multiple chemical processes for conversion to estrogen or progesterone.

Other properties wild yam is believed to have include anti-inflammatory, diuretic, antispasmodic, anti-rheumatic, expectorant, antidiabetic, antifungal and anticancer. Studies show wild yam contains many bioactive substances including steroidal saponins such as diosgenin and dioscin, alkaloids, tannins, phytosterols, proteins and starch. Diosgenin and dioscin are considered to be the primary therapeutic elements of wild yam, however, studies have shown no effect from the use of wild yam herbal supplements, since the body can’t convert it to a human hormone.

Topical use of wild yam cream is believed to reduce hot flushes and night sweats, and the antimicrobial and anti-inflammatory effects may promote skin health and reduce aging effects from exposure to sunlight (photoaging), however, there are no studies that confirm these effects. Wild yam herbal products are available as dried powders in the form of tablets and capsules, liquid extracts and topical creams.

Traditional uses of wild yam include:

• Menopausal symptoms
• Post-menopausal vaginal dryness
• Estrogen replacement
• Menstrual cramps
• Premenstrual syndrome
• Infertility
• Breast enlargement
• Osteoporosis
• Libido enhancement
• Nausea and morning sickness
• Inflammation
• Muscle spasms
• Arthritis
• Gallbladder problems
• Colic
• Diverticulosis
• High cholesterol
• Cough
• Asthma
• Skin health

• Wild yam may have estrogen-like activity. Do not use wild yam if you have hormone sensitive conditions including:
  • Endometriosis
  • Uterine fibroids
  • Uterine cancer
  • Ovarian cancer
  • Breast cancer
• Use with caution if you have:
  • Diabetes
  • Kidney or liver disease
• Do not take wild yam if you have protein S deficiency, a blood disorder that can cause clot formation. The estrogen-like effect of wild yam may increase the risk of blood clots.

Common side effects (dose-dependent) of wild yam include:

• Gastrointestinal upset
• Nausea
• Vomiting
• Diarrhea
• Headache
• Allergic reactions including:
  • Rhinitis
  • Dermatitis
• Scar tissue formation (fibrosis) in kidney or liver with prolonged, excessive doses

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

There is insufficient research on wild yam to know what might be an appropriate dosage of wild yam. Dosage used in animal (mice) studies was 9.8 – 37.7mg/ kg of bodyweight, which roughly translates to an approximate human dosage range of 0.8 – 3mg/kg of bodyweight, however, there are no studies in humans to recommend this dosage.

Overdose

Wild yam overdose may cause gastrointestinal upset, nausea, vomiting, diarrhea and headache, which should resolve with discontinuation of wild yam and adequate fluid intake. Excessive use for prolonged periods may cause scar tissue formation (fibrosis) in the kidney and liver.  

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Wild yam has no known severe or serious interactions with other drugs.
• Moderate interactions of wild yam include:
  • estrogens
• Mild interactions of wild yam include:
  • anticoagulants
  • antidiabetic agents
  • hepatotoxic and nephrotoxic drugs
  • indomethacin
  • NSAIDs

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• There is no reliable information on the safety of wild yam use during pregnancy and breastfeeding. Avoid use.
• Never take any herbal product without first checking with your healthcare provider if you are pregnant or breastfeeding.

• Wild yam supplements are possibly safe for most adults taken orally in recommended dosages for up to 12 weeks, or applied topically on the skin.
• Scientific studies do not show evidence of any of the purported benefits of wild yam.
• If you do take wild yam, follow label instructions exactly. Natural products are not necessarily safe always and following suggested dosing is important.
• Check with your healthcare provider before taking any herbal product, including wild yam, particularly if you have any health conditions or if you are on any regular medication.
• Herbal products often contain many ingredients. Check labels for the components in the wild yam product you choose.
• Some wild yam products may have synthetic steroid added to them. Exercise caution and buy only products from reputed manufacturers. 
• Wild yam is marketed as an herbal supplement and is not regulated by the FDA. Products may differ in formulations and strengths, and labels may not always match contents. Exercise caution in choosing your product.
• Store wild yam products safely out of reach of children.
• In case of overdose and persistent symptoms, seek medical help or contact Poison Control.