Horehound (Marrubium vulgare L.), commonly known as white horehound, is a European native of the Lamiaciae or mint family. Other names for this ancient remedy include houndsbane, marrubium, eye of the star, seed of Horus, marvel, bulls’ blood, and houndsbane. Horehound is a hardy perennial that has naturalized throughout North America; it may be found in sunny, wayside places, thriving even in poor, dry soil.
The common name horehound comes from the Old English words har and hune, meaning downy plant. This descriptive name refers to the white hairs that give this herb its distinctive hoary appearance. Another suggested derivation is from the name of the Egyptian god of sky and light, Horus.
Horehound is one of the oldest known cough remedies. It was one of the herbs in the medicine chests of the Egyptian pharaohs. In Roman times, Caesar’s antidote for poison included horehound. The generic name is believed to be derived from the Hebrew word marrob, meaning bitter juice.
Horehound is one of the bitter herbs used in the Jewish Passover rites. Throughout its long history, white horehound has been valued not only as a folk remedy for coughs and congested lungs, but also as a magic herb for protection against the spells attributed to witches.
Black horehound (Ballota nigra), also known as black stinking horehound, is the smelly relative of white horehound. It belongs to the same family of plants as white horehound and is credited with some of the same medicinal applications. Both black and white horehound have been used to treat the bites of snakes and mad dogs, to rid the system of intestinal worms, and as antidotes to vegetable poisons.
Black horehound is considered to be especially useful in quelling the nausea associated with motion sickness, or to stop the vomiting brought on by nervous tension. It also acts as an emmenagogue, restoring a healthy balance to the menstrual cycle.
White horehound is a bushy plant that grows nearly 2 ft (61 cm) tall from a short, stout, and woody root. The small oval leaves are bitter to the taste, with a musky aroma. They are wrinkled and dark green on top, and pale with downy white hairs on the underside.
The leaves are opposite and deeply veined, growing on hairy, square, branching stems also covered with downy white hairs. The lower leaves of white horehound have long stalks, while the upper leaves are smaller and stalkless. The small white flowers form dense whorls at the leaf axils, blooming in the second year of growth from June to August.
Flowers are tubular with two lips. Four small shiny dark brown seeds are carried in each nutlet after flowering. Horehound seeds have tiny barbs to attach to animal fur and clothing, while horehound blossoms attract bees to the garden.
White horehound is best known as a time-honored cough remedy, found in syrup, candy and tea preparations. The aerial parts of the plant are used medicinally. The active ingredients include sesquiterpene bitters, marrubin, volatile oil, tannins, flavonoids, and mucilage. White horehound is antiseptic. An infusion used as a wash, or a preparation of horehound salve is useful to disinfect wounds.
A cold infusion of white horehound acts as a bitter digestive tonic and will stimulate the flow of bile from the gall bladder. It is diuretic and may also relieve flatulence and stimulate appetite. White horehound stimulates discharge of bronchial mucus, loosening and expelling phlegm.
It is beneficial in the treatment of croup, bronchitis, and whooping cough, and has been used in the past in the treatment of tuberculosis, once known as consumption. White horehound is also said to normalize cardiac arrhythmias. A warm infusion is diaphoretic, meaning that it will promote sweating. It has been used to break fevers and to treat jaundice and typhoid fever.
The finely chopped leaves, mixed with honey and chewed slowly, will ease a sore throat and relieve hoarseness. The herb was also used following childbirth to promote expulsion of the placenta. White horehound combines well with other herbs in medicinal infusions, including elecampane (Inula helenium L.) and licorice (Glycyrrhiza glabra).
Many of the time-tested traditional uses for this safe herbal remedy have not been clinically proven. White horehound has been approved for treatment of bronchial problems and as an appetite stimulant by the German E Commission—an advisory group on herbal medicines in that country.
The U.S. Food and Drug Administration (FDA), however, has declared horehound ineffective for its traditional medicinal use as a sore throat remedy, while approving it as a safe food additive.
It is possible, however, that horehound may prove to be useful in herbal treatments for inflammation. In 2002, French researchers reported isolating new glycoside compounds in horehound, one of which has anti-inflammatory activity.
In addition, a group of American researchers studying traditional Mexican herbal remedies for headache, asthma, arthritis, fever, and menstrual cramps found that horehound has a high antioxidant content that may explain its inclusion in folk remedies for these conditions.
Tincture: Combine 4 oz of finely-cut fresh horehound leaf (or 2 oz of dry powdered herb) with 1 pt of brandy, gin, or vodka in a glass container. There should be enough alcohol to cover the plant parts and have a 50/50 ratio of alcohol to water.
Cover and store the mixture away from light for about two weeks, shaking several times each day. Strain and store in a tightly-capped dark glass bottle. A standard dose is 10–15 drops of the tincture in water, up to three times a day.
Infusion: Place 2 oz of fresh horehound leaves in a warmed glass container. Bring 2.5 cups of fresh, nonchlorinated water to the boiling point and add it to the herbs. Cover. Infuse the tea for about ten minutes. Strain and sweeten to taste. Drink warm or cold, depending on the intended results. The prepared tea will store for about two days in the refrigerator. Drink three cups a day.
Syrup: Using fresh leaves, prepare a strong infusion of horehound using twice the amount of fresh herb. Combine the infusion with a 50/50 mixture of honey and brown sugar. Use 24 oz of sweetener for each 2.5 cups of the herbal infusion.
Heat the mixture in a glass or enamel pot and stir frequently as the mixture thickens. Cool and pour into clearly-labeled glass bottles. Refrigerate for storage. One teaspoonful of syrup may be taken three times a day, or every two hours if needed in acute illness.
Pregnant women should not self-medicate with horehound herbal preparations. Lactating women should also consult with a qualified herbalist before using the herb internally. Infants and children under two years of age should not be given horehound.
Do not use horehound medicinally if there is chronic disease of the gastrointestinal tract, such as ulcers, esophageal reflux, colitis, or diverticulosis. Large doses of horehound may have a purgative action. Very large doses may cause irregular heartbeat.
When horehound is taken internally, it may interfere with the absorption of iron and other minerals.
No interactions have been reported as of 2002 between horehound and standard pharmaceutical preparations. However, some anesthesiologists recommend that patients scheduled for any surgery requiring total anesthesia should discontinue all herbal preparations for 1–2 weeks before the operation. The reason for this precaution is that some herbal preparations appear to interfere with the action of inhaled anesthetics.