White Horehound 

Marrubium vulgare

Used for centuries, spoken of by both Dioscorides and Pliny, is long renowned for treating asthma, coughs, pulmonary consumptions, some liver and spleen disorders, and “filthy ulcers”. The format of ingestion and application is highly versatile. It can be used as a dry or fresh herb in tea or decoction, freshly juiced, added to vinegar, made into tincture or applied topically as a powder or bruised plant.
Today, it’s likely to be dispensed as a tincture, syrup or tea, but the taste is rather bitter. It’s also made into a therapeutic candy that you can find today.