Slippery Elm, its Biochemistry, and use as a Complementary and Alternative Treatment for Laryngeal Irritation

Slippery elm is an herbal medicine derived from the inner bark of the slippery elm (Ulmus rubra - also known as Red Elm or Indian Elm) tree. It has been used to treat edema and inflammation as an alternative/complimentary form of medicine for many years. In the United States, slippery elm is marketed commercially to treat upper airway inflammatory conditions, and its reported benefits in treating these conditions are ubiquitous in anecdotal contexts. Individuals with voice disorders and other inflammatory conditions of the upper airway (e.g., laryngitis) are increasingly seeking information related to the use of herbal medications such as slippery elm, although most clinicians are unfamiliar with these medications and do not understand their biological actions and purported benefits. Furthermore, no scientific evidence is available to support the validity of slippery elm’s use in treating upper airway inflammatory conditions. The purpose of this manuscript is to review the biochemical composition, biological actions, and purported societal use of slippery elm as a complementary or alternative medicine specific to upper airway inflammatory conditions, present results from a pilot study investigating the soothing effects of slippery elm on the tissue of the upper airway, and present a framework for potential scientific investigation of slippery elm and related herbal medications.