Slippery elm (Ulmus rubra, Ulmus fulva) is a deciduous tree that is native to North America, where its inner bark has been used for centuries as an herbal remedy.

Native Americans used slippery elm for healing various skin conditions, for treating coughs, and as an eye wash. Several tribes regularly consumed slippery elm as a food.

In the 1930s, Rene Caisse, a Canadian nurse, included slippery elm (along with Turkish rhubarb, sheep sorrel and burdock root) in her popular Essiac tea. In spite of no scientific proof of efficacy, this preparation is still promoted as an anticancer remedy. (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)

Richard Mabey, in The New Age Herbalist (Simon Schuster, 1988), calls slippery elm "both a food and a medicine." Because the bark contains several useful nutrients, it can be boiled to make a reasonably wholesome porridge. Easily digested, it is well tolerated by people with intestinal problems (and, once flavored with a bit of cinnamon or nutmeg, even children find it palatable).

Constituents of Slippery Elm

Slippery elm's main medicinal constituents are mucilage, which is composed of complex sugars and starches, and tannins, which are plant-based astringents.

The mucilage acts as an emollient and demulcent; it coats and soothes mucous membranes. Tannins help to shrink inflamed tissues.

Nutritional Content of Slippery Elm

Nutrients found in slippery elm bark include:

StarchesSugarsCalciumIodineBromineAmino acidsManganese (trace)Zinc (trace)Uses for Slippery Elm

The US Food and Drug Administration (FDA) has approved slippery elm as a safe and effective option for treating sore throat (pharyngitis) and respiratory symptoms, such as cough.

Ayurvedicand Chinese physicians include slippery elm in their pharmacopeia for bloody diarrhea. Other uses may include:

Mild respiratory ailmentsDiarrhea (orally or as an enema)Wounds, skin ulcerations, burns, and rashes (external applications)Vaginitis (douche)Hemorrhoids (external application or enema)Mild laxativeSkin softenerGastritis and peptic ulcerA 2002 in vitro study demonstrated that slippery elm might prove useful for inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis. (Langmead L, 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)Availability, Preparations and Dosages of Slippery Elm

Commercially available forms:

Tablets or capsulesLozengesFinely powdered bark for beveragesCoarsely powdered bark for poultices and plastersLarge slices of bark are not legally available in several states due to their historical use as abortifacients--they were inserted into the cervix and allowed to expand, thus leading to termination of pregnancyBasic instructions for bark preparations (and recommended adult dosages) are:Decoction: Gently simmer eight parts water and one part bark for an hour or longer until mixture is mucilaginous. Add to juice, yogurt, or oatmeal and take as needed.Infusion: Pour two cups boiling water over two tablespoons finely powdered bark; steep for about 5 minutes. Drink three times daily.Capsules or tablets (250 to 500 mg): take two three times daily.Lozenges: per instructions on label.External applications: Mix one part coarse bark to four to six parts boiling water. Stir until comfortably warm. Apply as poultice.Dosages for children are based on weight. Above recommendations are based on an adult weighing 150 lbs. A child weighing 50 pounds would receive 1/3 the adult dose.

Slippery elm is a safe and effective herbal therapy; it is also a wholesome food. The only precaution in its use is to avoid taking it simultaneously with medications, as it may impair drug absorption.