According to the University of Maryland's Medical Center, slippery elm is a Native American herbal remedy that has been used to relieve common cold symptoms, including cough, sore throat, upset stomach and diarrhea.

Slippery elm is a tree, but the medicinal part is taken from the inner bark. It is known as the slippery elm because, when mixed with water, it becomes a slick gel. This gel is rich with antioxidants and coats your throat, stomach lining and intestines, providing relief.

Slippery elm can be made into a tea, or it can be purchased in the form of a throat lozenge or in a powdered bark form.