Scientific Name: Slippery elm
Other Names: American Elm, Elm, Indian Elm, Japanese Elm, Moose Elm, Red Elm, Sweet Elm, Ulmus fulva, Ulmus rubra, Winged Elm

Who is this for?

Uses

All species of elm contain varying amounts of mucilage, a substance that swells up and becomes slippery, but does not dissolve when mixed with fluids. One kind, slippery elm, generally has more mucilage than other elms. Taking mucilage may help to relieve coughs and other symptoms that are associated with respiratory conditions such as bronchitis. Mucilage may also make slippery elm useful for treating gastrointestinal (GI) conditions because it coats the mouth, esophagus, and GI tract with a slick residue. Therefore, it may soothe a sore throat, help to alleviate the pain of colic or stomach ulcers, and relieve inflammatory bowel conditions. Additionally, slippery elm may promote the production of GI mucus, further protecting the linings of the stomach and intestines. Additionally, results from a recent laboratory study suggest that slippery elm contains antioxidants that may reduce intestinal inflammation. Antioxidants are thought to protect body cells from damage caused by a chemical process called oxidation. Oxidation produces oxygen free radicals, natural chemicals that may suppress immune function. No human studies have been conducted to confirm any of these traditional uses of slippery elm, however.

Slippery elm may also be used to treat constipation. In the GI tract, the mucilage in slippery elm absorbs water. However, because the body cannot digest mucilage, the soft mass that it forms moves through the intestines. Additionally, it may prompt muscles in the intestines to contract. Both effects may help to relieve constipation, but they have not been proved in human studies.

Topically, slippery elm may be applied to the skin surface to relieve minor injuries such as burns, cold sores, razor burn, scrapes, and sunburn. Typically applied as a poultice—a soft cloth soaked in a medication and applied to an injured area of skin—slippery elm has also been made into salves by mixing it with an oily ointment base.

Precautions

The outer bark of slippery elm is known to contain chemicals that may cause pregnant women to miscarry. Although the inner bark, which is used in medicine, is not believed to contain these chemicals, pregnant women are still advised not to take slippery elm.

What side effects should I watch for?

Applying slippery elm to the skin may cause burning, itching, rash, redness, or scaling at the site of application.

Touching slippery elm products or breathing slippery elm tree pollen may cause allergic reactions in individuals who are sensitive to them.

What interactions should I watch for?

No interactions have been identified between slippery elm and drugs, other herbal products, or foods. However, because the mucilage that slippery elm contains may coat the stomach and intestines, it may block or delay the absorption of drugs or nutrients. If slippery elm is taken by mouth, the longest amount of time possible—at least 2 hours—should be allowed between taking slippery elm and eating or taking medications.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how slippery elm interacts with drugs, other herbals, and foods and the severity of those interactions, please use our Drug Interactions Checker to check for possible interactions.

Should I take it?

Several species of elm trees are thought to have originated in the eastern part of North America—particularly in the Appalachian Mountain region. Although elm leaves were collected, dried, and used occasionally as a tea or skin wash; the “inner” bark (the light-colored, spongy layer between the rough “outer” bark and the wood of the tree) of the slippery elm was most used by Native People and colonists. Some used the inner bark for food—it is easily digested and it is high in carbohydrates. Early colonists made a pudding of elm with milk and eggs; they used it to thicken jelly; they added it to grease to prevent rancidity; and they carried it on trips as a light weight “survival” food. For medicine, slippery elm was multi-purpose. It was applied to treat arthritis, gout, toothache, and all kinds of skin injuries. Orally, it was used to eliminate intestinal worms as well as to relieve coughs and stomach aches. It was used to waterproof baskets, canoes, and dwelling places, as well.

The wood of slippery elm has a darker reddish color and a different structure than most other elms. Because the grain of slippery elm wood is short and twisty, it is more flexible than other woods. In earlier times, it was used for bows and arrows, crates, fence posts, and tool handles; but not for lumber.

Slippery elm’s inner bark continues to be used today, even though the numbers of all types of elm trees in the United States were drastically reduced by Dutch Elm disease during the 1970’s. In the spring, sections of slippery elm bark are removed carefully from the trunk or large limbs of mature trees. If large amounts are taken the tree will die, and young slippery elm trees must be at least 10 years old to have enough inner bark to harvest. The dried inner bark used to be sold in chunks, but now it is most often processed commercially. After the light brown inner bark is separated from the rough, darker outer bark, the inner bark is dried and then shredded or powdered. Large scale processing of inner slippery elm bark is dangerous because the powder is very flammable. Like grain dust in silos, it may explode and burn under certain conditions. Currently, slippery elm is included in an herbal remedy known as Essiac. This preparation, which also contains burdock root, sheep sorrel, turkey rhubarb root, and possibly other herbals, is sold to treat cancer. No scientific evidence from laboratory, animal, or human studies support the use of Essiac for any condition.

Dosage and Administration

The most common commercial products made from slippery elm are throat lozenges. It is also sold in oral forms such as liquid tinctures and capsules. The capsules should be taken with a full glass of water because they swell when wet. They may cause a blockage of the esophagus if they become stuck in the throat. Slippery elm products have varying recommendations for use, so the directions on the package that is purchased should be followed.

Slippery elm may be made into a drink or a thin cereal-type food (usually called “gruel”) by mixing about one teaspoon of the powdered bark into about an ounce of cold water. Once the powdered slippery elm bark is dissolved, up to 8 ounces of boiling water or other liquid may be added. Slippery elm gruel has been used as food for babies and individuals who are unable to eat solid foods. Both slippery elm gruel and drinks made from slippery elm have a thick texture and a bland taste, so they are often flavored before consumption.

Summary

Slippery elm is included in cough lozenges and other products to treat coughing. It may also soothe the gastrointestinal tract and help relieve constipation, when it is taken by mouth. Applied topically, it may help to soothe and heal skin conditions.

Risks

Using inner bark of slippery elm is not known to cause problems during pregnancy. However, if any of the outer slippery elm bark is ingested by a pregnant woman, a miscarriage is a remote possibility.

Side Effects

No side effects have been attributed to taking slippery elm by mouth. However, it may cause rashes or other skin irritation if it is applied or handled.

Interactions

Although slippery elm is not known to interfere with any drugs, other herbals, or foods; taking it by mouth may slow down or stop absorption of other substances from the intestines.

Last Revised July 18, 2007

References

Anon. Essiac for cancer? Treatment Update. 1998;10(5):4-5.

Anon: Slippery elm. In: DerMarderosian A, Beutler JA, eds. Facts and Comparisons: The Review of Natural Products. St. Louis, MO, Facts and Comparisons. February 1999.

Czarnecki D, Nixon R, Bekhor P, Mason G. Delayed prolonged contact urticaria from the elm tree. Contact Dermatitis. 1993;28(3):196-197.

Das S, Shillington L, Hammett T. Non-timber forest products. Fact sheet no. 17. Slippery elm. Special Forest Products Program, Virginia Technical University. January 2001. Available at: http://www.sfp.forprod.vt.edu/factsheets/elm.pdf. Accessed November 26, 2003.

Day S. Slippery elm - Ulmus fulva. Alternative HealthZine. 2000;10:2. Available at: http://www.alternative-healthzine.com/html/1100_2.html. Accessed November 26, 2003.

Division of Forestry. Ohio Department of Natural Resources. Slippery elm (Ulmus rubra). No date given. Available at: http://www.dnr.state.oh.us/tabid/5366/default.aspx. Accessed July 9, 2007.

Felter HW, Lloyd JU. King's American Dispensatory. Eighteenth Edition. Third Revision. Cincinnati, Ohio. Ohio Valley Co. 1898. Available at: http://www.ibiblio.org/herbmed/eclectic/kings/intro.html. Accessed: November 21, 2003

Grieve M. Elm, slippery. In: A Modern Herbal. New York: Dover Publishers, 1971. Available at: http://www.botanical.com/botanical/mgmh/mgmh.html Posted 1995. Accessed November 21, 2003.

Hoffmann DL. Slippery elm. Herbal Materia Medica. No date given. Available at: http://www.healthy.net/asp/templates/article.asp?PageType=article&ID=1460. Accessed November 26, 2003.

Jellin JM, Gregory P, Batz F, Hitchens K, et al, eds. Pharmacist's Letter/Prescriber's Letter. Natural Medicines Comprehensive Database, 3rd Edition. Stockton CA: Therapeutic Research Facility, 2000.

Kemper KJ. Slippery elm. The Longwood Herbal Task Force. Revised September 15, 1999. Available at: http://www.mcp.edu/herbal/slipperyelm/slipperyelm.pdf Accessed: November 26, 2003.

Kim KS, Lee SD, Kim KH, Kil SY, Chung KH, Kim CH. Suppressive effects of a water extract of Ulmus davidiana Planch (Ulmaceae) on collagen-induced arthritis in mice. Journal of Ethnopharmacology. 2005;97(1):65-71.

Langmead L, Dawson C, Hawkins C, Banna N, Loo S, Rampton DS. Antioxidant effects of herbal therapies used by patients with inflammatory bowel disease: an in vitro study. Alimentary Pharmacology and Therapeutics. 2002;16(2):197-205.

Lee SJ, Oh PS, Ko JH, Lim K, Lim KT. Protective effect of glycoprotein isolated from Ulmus davidiana Nakai on carbon tetrachloride-induced mouse liver injury. Journal of Pharmacy and Pharmacology. 2006;58(1):143-152.

Leonard SS, Keil D, Mehlman T, Proper S, Shi X, Harris GK. Essiac tea: scavenging of reactive oxygen species and effects on DNA damage. Journal of Ethnopharmacology. 2006;103(2):288-296.

Majchrowicz MA. Essiac. Notes from the Underground. 1995;29(Winter):6-7.

MedLine Plus. Essiac. September 1, 2005. Available at: http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-essiac.html. Accessed June 8, 2006.

Tai J, Cheung S. In vitro culture studies of FlorEssence on human tumor cell lines. Phytotherapy Research. 2005;19(2):107-112.

Weber RW. American elm (Ulmus americana) is a native tree that has had a wide range from the entire eastern states through the central plains. Annals of Allergy, Asthma and Immunology. 2001;86(2):A7.

Zick SM, Sen A, Feng Y, Green J, Olatunde S, Boon H. Trial of Essiac to ascertain its effect in women with breast cancer (TEA-BC). Journal of Alternative Complementary Medicine. 2006;12(10):971-980.

Last Revised July 18, 2007

Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.

In general, herbal products are not subject to review or approval by the U.S. Food and Drug Administration (FDA). They are not required to be standardized, meaning that the amounts of active ingredients or contaminants they contain may vary between brands or between different batches of the same brand. Not all of the risks, side effects, or interactions associated with the use of herbal products are known because few reliable studies of their use in humans have been done.

This information is provided for your education only. Please share this information with your healthcare provider and be sure that you talk to your doctor and pharmacist about all the prescription and non-prescription medicines you take before you begin to use any herbal product.

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