(Marrubium Vulgare) Horehound is an expectorant herb, meaning that it has the properties to loosen mucus from the respiratory system. It’s been used since ancient days of the Egyptians and Romans for whooping cough and to alleviate sore throats. Horehound is a bitter herb due the Chemical marrubium. Bitter herbs are great for digestive issues. Horehound can be used to soothe ulcers, constipation, bloating, gas, and even to stimulate appetite. Horehound mixed with wild cherry bark and slippery elm, will give you a powerful concoction for respiratory infections.