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 number of essiac-like products such as Flor-Essence®.
There are no 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.
Indian elm, moose elm, red elm, rock elm, slippery elm, sweet elm, Ulmaceae, Ulmi rubrae cortex, Ulmus fulva Michaux, Ulmus rubra, winged elm.
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.
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 in this area before a strong recommendation 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.
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.