Slippery elm trees are native to North America and grow in moist but not waterlogged woods of eastern Canada and the United States.
The colonists were familiar with the use of bark from other elm species to treat coughs and sore throats in England and as a poultice for broken bones or wounds. It was also used to treat urinary tract infections. Native Americans used slippery elm bark topically for cuts, cold sores, and boils.
Evidently it was popular as a treatment for bruised “black eyes” and was used during the American Revolution to treat gunshot wounds.
The inner bark next to the wood is collected in the spring.
Old-time herbalist Tommie Bass considered it helpful for the stomach and useful in cough preparations.
The bark is sometimes chewed, frothing in the mouth and releasing the demulcent.
Slippery elm bark contains a mucilage.
Other components of the wood include beta-sitosterol and campestrol as well as some calcium oxalate. This inner bark contains only a little tannin.
Slippery elm bark has been used as a poultice for cuts and bruises, and also for aching joints due to gout or other causes.
Its principal use at this time is for sore throats. It is an ingredient in lozenges sold to soothe throat irritation.
Since sore throat and cough are often linked, slippery elm bark has also been used in cough remedies.
Tommie Bass used to combine slippery elm with wild cherry bark, sweet gum leaves, mullein, and sweetening for a homemade cough syrup. Chewing on the bark itself, if available, is said to produce the same effect and to have a pleasant taste.
The powdered bark may be mixed with liquid and swallowed for mild stomach irritation; it has a reputation for easing both constipation and diarrhea.
If using a lozenge, instructions on the label should be followed. Sucking on a lozenge gives a more lasting exposure than sipping a tea.
People with known allergies to elm bark should avoid it.
Elm pollen is quite allergenic. The bark may also cause contact dermatitis in sensitive individuals.
No interactions have been reported in the literature.