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Herb library · Herb · Marrubium vulgare

Horehound

A woolly, bitter member of the mint family, long made into cough syrups and candies. Its use for coughs, indigestion and appetite rests on tradition; a small trial found it did not lower blood sugar.

Traditional use

White horehound is a hoary gray-white plant native to Europe and naturalized across the United States. Its bitter leaves and flowering tops went into cough syrups and old-fashioned horehound candies. The European Medicines Agency accepts horehound teas, powders, juice and extracts to help bring up phlegm in a cough with a cold, for mild indigestion with bloating and wind, and for temporary loss of appetite, on the basis of long-standing use. In Mexican traditional medicine it is widely used for type 2 diabetes.

Traditional energetics

What studies show

  • Insufficient

    Cough with a cold, indigestion and loss of appetite: there is not enough evidence from clinical trials. The EMA's acceptance rests on long-standing use, with laboratory studies suggesting a plausible basis.

  • Limited· shows no benefit

    Blood sugar: in a small 2004 trial, 21 people with poorly controlled type 2 diabetes drank horehound tea for 3 weeks alongside their usual medicines; their fasting blood sugar fell by less than 1%, and cholesterol and triglycerides barely changed. The EMA reads it as showing no blood-sugar-lowering effect, and no effect on blood pressure.

Be careful of

Cautions

  • AllergyDo not use it if you are allergic to horehound or other plants of the mint family (Lamiaceae).
  • ConditionDo not use it with a blocked bile duct, bile duct inflammation, liver disease or bowel obstruction. Talk with a doctor first if you have an active stomach ulcer, gallstones or another gallbladder problem.
  • ConditionSee a doctor if a cough lasts longer than a week, or indigestion or loss of appetite longer than two weeks, or if symptoms get worse. Not recommended for children under 12.
  • NoteNo side effects had been reported when the EMA assessed it. Liquid extracts contain alcohol.
  • PregnancySafety in pregnancy and breastfeeding has not been established, and the EMA does not recommend it then.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

From the old books

What herbals and dispensaries of the past printed. History, in their words.

“It has a peculiar, rather agreeable, vinous, balsamic odor, and a very bitter, aromatic, somewhat acrid and persistent taste.”
Harvey Wickes Felter and John Uri Lloyd, King's American Dispensatory (1905), vol. 2, p. 1241. See the page of King's American Dispensatory, vol. 2, p. 1241 (opens in a new tab) · Read the full passage from King's American Dispensatory, vol. 2, p. 1241
“In large doses it purges. It enters into the composition of several syrups and candies.”
Harvey Wickes Felter and John Uri Lloyd, King's American Dispensatory (1905), vol. 2, p. 1241. See the page of King's American Dispensatory, vol. 2, p. 1241 (opens in a new tab) · Read the full passage from King's American Dispensatory, vol. 2, p. 1241

Sources

  1. Community herbal monograph on Marrubium vulgare L., herba (opens in a new tab) · EMA · read September 25, 2026
  2. Assessment report on Marrubium vulgare L., herba (opens in a new tab) · EMA · read September 25, 2026
  3. White horehound: summary for the public (opens in a new tab) · EMA · read September 25, 2026
  4. Clinical trial of Cecropia obtusifolia and Marrubium vulgare leaf extracts on blood glucose and serum lipids in type 2 diabetics (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.