Doctor's Best High Potency Serrapeptase supports and maintains healthy sinus and airway function as well as a healthy immune response. Serrapeptase is a proteolytic enzyme that comes from the Serratia bacteria species strain E15 and has been studied for over 40 years. Serrapeptase has protein, mucus and fibrin-digesting properties and has been shown to support immune function. It is also known for supporting circulation, cardiovascular health as well as joint health and comfort. As serrapeptase can be destroyed by stomach acids, High Potency Serrapeptase uses Serrateric™, a coating that protects the enzyme until it reaches the intestines and therefore aids absorption.