Medically reviewed on Jun 7, 2018
What is Horehound?
Horehound is native to Europe and Asia and has been naturalized to other areas, including the US. It is a perennial, aromatic herb of the mint family. The plant has oval leaves covered with white, woolly hairs, and bears small, white flowers.
Horehound also is known as hoarhound and white horehound.
What is it used for?
The leaves and flower tops of the horehound have long been used in home remedies as a bitter tonic for the common cold. Horehound has been used traditionally as an expectorant and continues to find a place in cough lozenges and cold preparations. It now is used primarily as flavorings in liqueurs, candies and cough drops. In addition, extracts of the plant were used for the treatment of intestinal parasites and as a diaphoretic and diuretic. A different genus, the black horehound (Ballota nigra), is a fetid-odored perennial native to the Mediterranean area that sometimes is used as an adulterant of white horehound.
Horehound has been used as a vasodilator, diaphoretic, diuretic, and treatment for intestinal parasites. Initial animal studies indicate that horehound may have hypoglycemic effects and may influence bile secretion. The volatile oil of horehound has been reported to have expectorant and vasodilatory effects. Evidence is limited on these medicinal uses.
What is the recommended dosage?
Horehound is given for digestive complaints as a crude herb at a daily dose of 4.5 g and as a pressed juice of the herb at 30 to 60 mL.
Contraindications have not yet been identified.
Information regarding safety and efficacy in pregnancy and lactation is lacking. Avoid use. Horehound has emmenagogue (to stimulate menstrual flow) and abortive effects.
None well documented.
Large doses may induce cardiac irregularities.
Marrubiin (the volatile oil) has an LD50 of 370 mg/kg when administered orally to rats.