In a double-blind study, a proprietary product containing marshmallow root, licorice root, and elm bark (Throat Coat) was effective in providing rapid, temporary relief of sore throat pain in people with acute pharyngitis.² Throat Coat was taken as a tea in the amount of 5 to 8 ounces, 4 to 6 times per day, for two to seven days.

Herbs high in mucilage, such as slippery elm, mallow (Malvia sylvestris), and marshmallow, are often helpful for symptomatic relief of coughs and irritated throats. 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. 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.

A number of herbs have a rich history of use for treating coughs due to colds, bronchitis, or other mild conditions. Only a few studies have examined the effectiveness of these herbs. However, their effectiveness is well-known by practitioners of herbal medicine the world over. Among those herbs that have been shown to have some degree of cough-relieving activity are marshmallow,³sundew,⁴ and coltsfoot.⁵ Use of coltsfoot should be limited to preparations of the leaves and flowers only, as the root is high in pyrrolizidine alkaloids, constituents that may be toxic to the liver.

Other herbs traditionally used to treat reflux and heartburn include digestive demulcents (soothing agents) such as aloe vera, slippery elm, bladderwrack, and marshmallow.⁶ 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.⁷ 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 ginger, licorice, and slippery elm.

The mucilage content in 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. Marshmallow and bladderwrack may be used the same way as slippery elm.⁸

Demulcent herbs, such as marshmallow, slippery elm, and 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.⁹

Marshmallow is high in mucilage. High-mucilage-containing herbs have a long history of use for irritated or inflamed mucous membranes in the digestive system, though no clinical research has yet investigated effects in people with peptic ulcer.¹⁰

Aloe vera juice has anti-inflammatory activity and been used by some doctors for people with UC. In a double-blind study of people with mildly to moderately active ulcerative colitis, supplementation with aloe resulted in a complete remission or an improvement in symptoms in 47% of cases, compared with 14% of those given a placebo (a statistically significant difference).¹¹ No significant side effects were seen. The amount of aloe used was 100 ml (approximately 3.5 ounces) twice a day for four weeks. Other traditional anti-inflammatory and soothing herbs, including calendula, flaxseed, licorice, marshmallow, myrrh, and yarrow. Many of these herbs are most effective, according to clinical experience, if taken internally as well as in enema form.¹² Enemas should be avoided during acute flare-ups but are useful for mild and chronic inflammation. It is best to consult with a doctor experienced with botanical medicine to learn more about herbal enemas before using them. More research needs to be done to determine the effectiveness of these herbs.

Doctors sometimes use a combination of herbs to soothe inflammation throughout the digestive tract. One formula contains marshmallow, slippery elm, cranesbill, and several other herbs.¹³ 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.

Herbs high in mucilage, such as marshmallow or slippery elm, may help reduce the irritation to the walls of the intestinal tract that can occur with diarrhea. A usual amount taken is 1,000 mg of marshmallow extract, capsules, or tablets three times per day. Marshmallow may also be taken as a tincture in the amount of 5–15 ml three times daily.¹⁴

Traditionally, herbs that have a soothing action on bronchioles are also used for asthma. These include marshmallow, mullein, hyssop, and licorice. Elecampane has been used traditionally to treat coughs associated with asthma.¹⁵

Several other herbs have been used as part of an approach for women with mild cervical dysplasia, including myrrh, echinacea, usnea, goldenseal, marshmallow, and yarrow.¹⁶ These herbs are used for their antiviral actions as well as to stimulate tissue healing; they are generally administered in a suppository preparation. No clinical trials have proven their effectiveness in treating cervical dysplasia. A doctor should be consulted to discuss the use and availability of these herbs.