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Slippery elm (Ulmus rubra Muhl or Ulmus fulva Michx)
Generic Name: slippery elm
CategoryHerbs & Supplements
The slippery elm is native to eastern Canada and the eastern and central United States where it is found mostly in the Appalachian Mountains. Its name refers to the slippery consistency the inner bark assumes when it is chewed or mixed with water. Slippery elm inner bark has been used historically as a demulcent, emollient, nutritive, astringent, anti-tussive, and vulnerary. It is included as one of four primary ingredients in the herbal cancer remedy, Essiac®, and in a number of Essiac-like products such as Flor-Essence®.
There is a lack of scientific studies evaluating the common uses of this herb, but due to its high mucilage content, slippery elm bark may be a safe herbal remedy to treat irritations of the skin and mucus membranes.
Although allergic reactions after contact have been reported, there is no known toxicity with typical dosing when products made only from the inner bark are used. Inner bark of slippery elm should not be confused with the whole bark, which may be associated with significant risk of adverse effects. Bark of Californian slippery elm (Fremontia Californica) is often used similarly medicinally, but it is not botanically related.
EvidenceDISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Slippery elm is found as a common ingredient in a purported herbal anticancer product called Essiac® and a number of Essiac-like products. These products contain other herbs such as rhubarb, sorrel, and burdock root. Currently, there is not enough evidence to recommend for or against the use of this herbal mixture as a therapy for any type of cancer.
Traditionally, slippery elm has been used to treat diarrhea. While theoretically the tannins found in the herb may decrease water content of stool, and mucilage may act as a soothing agent to inflamed mucous membranes, there is no reliable scientific evidence to support this indication. Systematic research is necessary in this area before a clear conclusion can be drawn.
Slippery elm is traditionally used to treat inflammatory conditions of the digestive tract such as gastritis, peptic ulcer disease, or enteritis. It may be taken alone or in combination with other herbs. Additional study is needed in this area before a clear conclusion can be drawn.
Slippery elm is commonly used to treat sore throats, most typically taken as a lozenge. Supporting evidence is largely based on traditional evidence and the fact that the mucilages contained in the herb appear to possess soothing properties. Additional study is needed in this area before a strong recommendation can be drawn.
TraditionWARNING: DISCLAIMER: The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Abscesses, abortifacient, abrasions, acidity, anal fissures, antihelminthic (expels worms), antioxidant, boils, bronchitis, burns, carbuncles, colitis, cold sores, congestion, constipation, cough, cystitis, demulcent, diuretic, diverticulitis, dysentery, emollient, eruptions, esophageal reflex, expectorant, gout, gynecological disorders, heart burn, hemorrhoids, herpes, immunomodulation, inflammation, laxative, lung problems, milk tolerance, pleurisy, psoriasis, rheumatism, swollen glands, synovitis, syphilis, toothache, typhoid fever, ulcerative colitis, vaginitis, varicose ulcers, wounds.
Adults (18 years and older)
There is no proven effective dose for slippery elm in adults. Slippery elm could theoretically slow down or decrease absorption of other oral medications due to hydrocolloidal fibers, although there is a lack of actual interactions reported. Teas, decoctions, liquid extracts, powdered inner bark preparations, and capsules/tablets are all commercially available.
Slippery elm bark 400-500-milligram tablets or capsules taken three or four times daily have been studied, although strengths may vary due to lack of standardization. Lower doses of 200-milligram capsules twice or three times per day have been used for bronchitis.
Slippery elm has been applied on the skin for wound care and inflammation. Typically, the coarse powdered inner bark is mixed with boiling water to make a paste. Various concentrations and application schedules have been used.
Children (younger than 18 years)
Traditionally, it has been accepted that slippery elm can be used safely in children complaining of stomach upset and diarrhea. However, there are no safety studies conducted in this area, and therefore use in children should only be under the strict supervision of a licensed healthcare professional.
SafetyDISCLAIMER: Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.
Known allergy or hypersensitivity such as hives (urticaria) has been reported with slippery elm; some persons may have contact sensitivity to elm tree pollen (or sensitivity when breathing it in), but the frequency of allergic reactions to medicinal use of elm bark products is extremely rare.
Side Effects and Warnings
Contact dermatitis and urticaria have been reported after exposure to slippery elm or an oleoresin contained in the slippery elm bark. Based on historical accounts, whole bark of slippery elm (but not inner bark) may possess abortifacient properties.
Pregnancy and Breastfeeding
Interactions with Drugs
Slippery elm could theoretically slow down or decrease the absorption of other oral medications due to hydrocolloidal fibers, although there is a lack of actual interactions reported. Slippery elm contains tannins, which could theoretically decrease the absorption of nitrogen-containing substances such as alkaloids, although there is a lack of actual interactions reported.
Interactions with Herbs and Supplements
Slippery elm could theoretically slow down or decrease the absorption of other herbs or supplements taken by mouth due to hydrocolloidal fibers, although there is a lack of actual interactions reported. Slippery elm contains tannins, which could theoretically decrease the absorption of nitrogen-containing substances such as alkaloids, although there is a lack of actual interactions have been reported.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Tracee Abrams, PharmD (University of Rhode Island); Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Dawn Costa, BA, BS (Natural Standard Research Collaboration); Sadaf Hashmi, MD, MPH (Natural Standard Research Collaboration); Michael Smith, MRPharmS, ND (Canadian College of Naturopathic Medicine); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Wendy Weissner, BA (Natural Standard Research Collaboration).
BibliographyDISCLAIMER: Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
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