The uses of horehound have come down to us from the Greeks, Romans, and from our own North American herbal traditions. 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
You can still find old fashioned horehound cough drops sold in stores, but homemade ones are best. Keep a supply on hand for winter colds - makes a great seasonal gift too.