Native American tribes discovered that by scraping away the rough outer bark of the majestic slippery elm tree (Ulmus rubra), they could uncover a remarkable healing substance in the inner bark. They beat the bark into a powder and added water to create a "slippery" concoction ideal for soothing mucus membranes and healing scrapes.
Long recognized by health authorities in the United States as an effective medicine, slippery elm bark presently has the approval of the Food and Drug Administration as a nonprescription demulcent (soothing agent) that can be taken internally.
The popularity of slippery elm bark has endured, no doubt, because it works so well for coating and soothing irritated or inflamed mucous membranes. This is the work of an ingredient in the inner bark called mucilage, a gummy, gel-like substance that when ingested forms a protective layer along the throat, digestive tract, and other areas. Astringent compounds in the herb called tannins help tighten and constrict tissue.
There are no known drug or nutrient interactions associated with slippery elm. If an allergic rash develops when slippery elm is applied to the skin, discontinue its use in all forms.