Pomo Valley's Formula #4 is best known for relief of Hay Fever. But others also find relief when dealing with Asthma, Pleurisy and mucus. This is a must have. The herb combination consist of: Blessed Thistle, has an effect in helping relieve headaches and migraines. Skull Cap, a powerful tonic and relaxant that is calming, soothing and nutritive. and Pleurisy Root, used to break up congestion in lungs and upper respiratory areas. This combination works together perfectly. Thanks for your interest enjoy!!