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.