Herbs & Botanicals
What is slippery elm? What is it used for?
Slippery elm is a medium-sized tree native to North America. It can reach a height of more than 65 feet, with reddish-brown branches that grow downward and long, green leaves that darken in color.
What makes slippery elm distinctive from most other trees is its bark. The tree's outer bark has a gummy feel and a slight (but distinctive) odor. The inner bark contains a form of mucilage, which gives the tree its healing properties.
Mucilage contained in the inner bark of slippery elm consists of a variety of chemical compounds, including hexoses, pentoses, methylpentoses, polyuronides and hexosans. It also contains tannins, starch, minerals, phytoesterols, sesquiterpenes, calcium oxalate and cholesterol.
Traditionally, slippery elm has been used as a skin softener and cough medicine. It is used externally to treat wounds, burns and other skin conditions, as well as vaginitis and hemorrhoids. Powdered forms can be taken internally for gastritis, duodenal ulcers, colitis, diarrhea, and oral inflammations. Scientific studies have found slippery elm to be effective in treating sore throats and coughs - so much so, in fact, that the U.S. Food and Drug Administration has proclaimed slippery elm a safe and effective remedy for soothing throat and respiratory infections.
How much slippery elm should I take?
The amount of slippery elm to be given depends on the age and size of the person taking it. For adults, two to four capsules (500 milligrams) of powdered slippery elm bark are recommended, depending on the condition. A slippery elm tea can also be made by boiling small pieces of the bark in water for 10 to 15 minutes, then letting the tea cool before drinking. For external conditions, health practitioners recommend coarse powdered bark be mixed with boiling water to use as a poultice. Make sure adequate mucilage is obtained for consistency and viscosity.
What forms of slippery elm are available?
Some stores sell whole pieces of inner bark, usually two to three feet long and 1/8 to 1/16 of an inch in thickness, for commercial preparations. Slippery elm is also available in a finely powdered form for drinks and a coarsely powdered form for poultices.
What can happen if I take too much slippery elm? Are there any interactions I should be aware of? What precautions should I take?
There are no known side-effects or health hazards for slippery elm when it is properly administered in the recommended doses. No adverse interactions with other substances have been reported; however, because of its high mucilage content, it may interfere with the absorption of some oral medications taken at the same time. As always, make sure to consult with a licensed health care provider before taking slippery elm or any other dietary supplement or herbal remedy.
- Blakley T. Slippery elm: comparative study of the effects of plant spacing on plant development and yield. Research Farm Proposal No. 6088. Collaborating Team, The National Center for the Preservation of Medicinal Herbs. Project Period 1998-2008. Available online.
- Gruenwald J, Brendler T, Jaenicke C (eds.) PDR for Herbal Medicines, 2nd ed. Montvale, NJ: Medical Economics Company, 2000, p. 697.
- Kaegi E. Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 1998;158(7):897-902.
- Langmead L, Dawson C, Hawkins C, et al. Antioxidant effects of herbal therapies used by patients with inflammatory bowel disease: an in vitro study. Aliment Pharmacol Ther 2002;16(2):197-205.
- Rotblatt M, Ziment I. Evidence-Based Herbal Medicine. Philadelphia: Hanley & Belfus, Inc., 2002, pp. 337-338.