The uses of horehound have come down to us from the Greeks, Romans, and from our own North American herbal traditions. You can still find old fashioned horehound cough drops sold in pharmacies, but homemade ones are best in my opinion. Horehound was an accepted medicinal plant in the U.S. Pharmacopoeia until 1989 and is still endorsed in Europe as an effective cold medicine. 418
For an ordinary cold a simple infusion of horehound is generally sufficient in itself to ease sinus congestion and chesty coughs. The bitter taste of the herb is commonly disguised by plenty of honey in horehound cough drops.