Marshmallow has demulcent, expectorant, diuretic, and emollient properties. It is generally used in ailments of the lungs and the urinary systems, specifically in urethritis and kidney stones. It is also used for digestive and skin problems, specifically inflammations of the mouth, gastritis, peptic ulcer, enteritis, and colitis. It increases the flow of breast milk, soothes the bronchial tubes, and has been used to treat constipation and irritable bowel syndrome. Topical applications include, in cases of varicose veins, ulcers, abscesses, boils, cosmetic treatment for the skin and as a gargle to treat mouth and throat ulcers.

Marshmallow has been used in traditional European medicine for more than 2,000 years, and its therapeutic use was first recorded in the 9th Century. Since Egyptian antiquity marshmallow root has been used in a honey-sweetened confection for treatment of sorethroat.

Marshmallow leaf and root are commonly used by mouth to treat stomach ulcers, diarrhea, constipation, swelling of the stomach lining, and pain and swelling of the mucous membranes that line the respiratory tract. But there is limited scientific evidence to support these and other uses.