Known interactions

No interactions found.

On-line White Horehound

Scientific Name: White Horehound

Other Names: Hoarhound, Horehound, Houndsbene, Marrubii herba, Marrubium vulgare, Mastranzo

Who is this for?

Note: White horehound should not be confused with black horehound (Ballota nigra). The two plants have very different uses even though they look similar and grow in similar areas.

White horehound is best known as an oral remedy for bronchitis and other respiratory conditions that cause congestion. Chemicals in white horehound are believed to relax the bronchial tubes in the lungs. In addition, they may promote mucus production – making mucus more watery and possibly easier to eliminate from the body by coughing. All these potential effects may relieve general lung congestion.

Historically, white horehound has also been taken to relieve minor gastrointestinal conditions. Its bitter taste may increase appetite, and it may also reduce gas in the stomach. Additionally, in animal studies, white horehound has produced increases in bile production, which may not only improve appetite, it may relieve indigestion, as well. Some of the chemicals in white horehound have also been shown in laboratory studies to have mild diuretic and laxative effects, meaning that they may promote the elimination of both urine and solid waste from the body. Therefore, they may be slightly useful to lessen mild swelling, such as may be associated with menstrual periods.

In separate animal studies and under laboratory conditions, white horehound and chemicals extracted from it have shown some other potential effects. They may have some effectiveness for treating abnormal heart rhythms and high blood pressure – possibly through the relaxing effect they may have on blood vessels. Extremely large doses, however, may disturb heartbeat. Early results from animal studies show possible uses for white horehound in treating diabetes, high cholesterol, and pain. However, none of these possible effects have been well-studied in humans.

When should I be careful taking it?

White horehound should not be taken by women who know or suspect they are pregnant because it may affect muscles in the uterus. A slight possibility also exists that white horehound could cause uterine hemorrhage (excessive bleeding from the uterus). Theoretically, a miscarriage may be caused by either effect.


White horehound contains chemicals that may alter heart rhythm. Therefore, individuals who have heart conditions should avoid taking large amounts of white horehound or using it for long periods of time.

White horehound may possibly have some ability to lower blood sugar and/or blood pressure. To keep blood sugar from getting too low, individuals who take insulin or oral agents for diabetes should use white horehound cautiously and monitor blood sugar levels carefully while taking it. Similarly, individuals taking medicine to lower blood pressure should also limit taking white horehound due to a small possibility that blood pressure may become too low.

What side effects should I watch for?

In some animal studies, white horehound was shown to have effects on heart rhythm. Although no human studies have been performed to verify these results, individuals who have heart conditions should avoid using white horehound.

Very large doses of white horehound have been reported to have a strong laxative effect. In general, no more than 4,000 mg (4 grams) of the dried herb should be used in a day.

Less Severe Side Effects

A few individuals may have developed an itchy rash from handling or coming in contact with the white horehound plant — even after it has been dried. It is a member of the mint family of plants, so individuals who are sensitive to other types of mint may also be sensitive to white horehound.

What interactions should I watch for?

No interactions between white horehound and prescription drugs, non-prescription drugs, other herbal products, or foods have been reported. However, because few reliable studies of white horehound have been conducted in humans, its possible interactions with drugs, foods, and other dietary supplements are not understood completely. Individuals who consider taking it should be sure that a doctor or pharmacist is aware of all the prescription and non-prescription medicines they take before they begin to use white horehound or any other herbal supplement.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.

Should I take it?

White horehound is a shrubby, perennial plant that probably grew first in northern Europe, but that now grows wild in most parts of the world. Considered a weed in crop- and livestock-producing areas, it spreads rapidly and grows well in marginal locations such as along railroad tracks. A member of the mint family, it has the square stems that are characteristic of the mints. Its clusters of white flowers bloom at the same points as its distinctive leaves. The stems and leaves of white horehound plants are covered in whitish fuzz. Both the flowers and the woolly leaves give white horehound its name and also distinguish white horehound from similar types of plants. Fresh leaves have a stale smell; both fresh and dried white horehound have a bitter taste that has been described as faintly minty and apple-like. In the United Kingdom, it has been used to flavor a beer known as horehound ale.

The “aerial parts” (flowers, leaves, and stems) of white horehound are collected and dried for use as medicine. Dried white horehound contains a volatile oil known as marrubiin, which may not be present in fresh white horehound plants. Also called essential oils, volatile oils possess the characteristic smell and taste of the plant. They usually evaporate quickly at room temperature. Due to lack of evidence proving its effectiveness, white horehound was removed in 1989 from the FDA’s list of active ingredients that are approved for use in non-prescription cough medicines. It can be sold as a dietary supplement; however, and it is still recognized as safe when used in small amounts to flavor beverages, candies, foods, and medicines.

Dosage and Administration

Note: White horehound should not be confused with black horehound (Ballota nigra), another product that is often called horehound. If white horehound is used, the label on the package that is purchased should clearly specify white horehound, and not just horehound, in the ingredients.

The U. S. Food and Drug Administration (FDA) classifies white horehound as "generally recognized as safe” (GRAS) when it is used as a flavoring in foods, beverages, or medicines. Although it is not FDA-approved for use as a medication, white horehound may be sold in the United States as a dietary supplement. It is available commercially in a number of oral preparations, mainly cough lozenges or syrups. White horehound is often combined with eucalyptus, marshmallow, or other herbals that may relieve lung congestion. Recommendations for its use vary, so the directions on the package that is purchased should be followed. The maximum amount that should be consumed in one day is 4,000 mg (4 grams).

Additionally, white horehound can be brewed into a tea using about a teaspoon of the fresh or dried flowers and leaves in one cup of boiling water. After being soaked for 10 to 15 minutes, the solid parts are strained out before drinking the tea. Because the taste of white horehound may be bitter, the tea is usually sweetened or combined with other strong flavorings such as cinnamon. To stimulate the appetite, white horehound tea is usually taken three times a day before meals. For relieving congestion, it may be used as needed, but no more than three times a day.


White horehound is used most often as a tea or syrup to relieve respiratory congestion. It may also improve appetite, relieve gastrointestinal bloating, and reduce mild swelling. Although preliminary laboratory and animal studies seem to show it may have some beneficial effects for other conditions, not enough research supports it for any medical use.


Because white horehound may affect muscles in the uterus, possibly resulting in a miscarriage, women who are pregnant or who may be pregnant should not use it. Individuals with heart conditions should also avoid using white horehound due to its possible effect on heart rhythm. Individuals with diabetes and/or high blood pressure should use it cautiously, if at all.

Side Effects

Large oral doses of white horehound may cause diarrhea. Touching it may result in an itchy rash.


No interactions between white horehound and prescription drugs, non-prescription drugs, other herbal products, or foods have been reported.


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(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)

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