Slippery Elm

Herbs high in mucilage, such as Reference slippery elm, mallow (Malvia sylvestris), and Reference marshmallow, are often helpful for symptomatic relief of coughs and irritated throats. Reference Mullein has expectorant and demulcent properties, which accounts for this herb’s historical use as a remedy for the respiratory tract, particularly in cases of irritating coughs with bronchial congestion. Reference Coltsfoot is another herb with high mucilage content that has been used historically to soothe sore throats. However, it is high in pyrrolizidine alkaloids—constituents that may damage the liver over time. It is best to either avoid coltsfoot or look for products that are free of pyrrolizidine alkaloids.

The mucilage of Reference slippery elm gives it a soothing effect for coughs. Reference Usnea also contains mucilage, which may be helpful in easing irritating coughs. There is a long tradition of using Reference wild cherry syrups to treat coughs. Other traditional remedies to relieve coughs include Reference bloodroot, Reference catnip, Reference comfrey (the above-ground parts, not the root), Reference horehound, Reference elecampane, Reference mullein, Reference lobelia, Reference hyssop, Reference licorice, Reference mallow, (Malvia sylvestris), Reference red clover, Reference ivy leaf, Reference pennyroyal (Hedeoma pulegioides, Mentha pulegium), Reference onion, (Allium cepa), and Reference plantain (Plantago lanceolata, P. major). None of these has been investigated in human trials, so their true efficacy for relieving coughs is unknown.

Doctors sometimes use a combination of herbs to soothe inflammation throughout the digestive tract. One formula contains Reference marshmallow, Reference slippery elm, Reference cranesbill, and several other herbs.² Marshmallow and slippery elm are mucilaginous plants that help soothe inflamed tissues. Cranesbill is an astringent. Clinical trials using this combination have not been conducted.

Demulcent herbs, such as Reference marshmallow, Reference slippery elm, and Reference bladderwrack, are high in mucilage. Mucilage might be advantageous for people with gastritis because its slippery nature soothes irritated mucus membranes of the digestive tract. Marshmallow is used for mild inflammation of the gastric mucosa.³

Other herbs traditionally used to treat reflux and Reference heartburn include digestive demulcents (soothing agents) such as Reference aloe vera, Reference slippery elm, Reference bladderwrack, and Reference marshmallow.⁴ None of these have been scientifically evaluated for effectiveness in GERD. However, a drug known as Gaviscon, containing magnesium carbonate (as an antacid) and alginic acid derived from bladderwrack, has been shown helpful for heartburn in a double-blind trial.⁵ It is not clear whether whole bladderwrack would be as useful as its alginic acid component.

Demulcents herbs may be used to treat indigestion and heartburn. These herbs seem to work by decreasing inflammation and forming a physical barrier against stomach acid or other abdominal irritants. Examples of demulcent herbs include Reference ginger, Reference licorice, and Reference slippery elm.

The mucilage content in Reference slippery elm appears to act as a barrier against the damaging effects of acid on the esophagus in people with heartburn. It may also have an anti-inflammatory effect locally in the stomach and intestines. Two or more tablets or capsules (typically 400–500 mg each) may be taken three to four times per day. Alternatively, a tea is made by boiling 1/2–2 grams of the bark in 200 ml of water for 10 to 15 minutes, which is then cooled before drinking; three to four cups a day can be used. Tincture (5 ml three times per day) may also be taken but is believed to be less helpful. Reference Marshmallow and bladderwrack may be used the same way as slippery elm.