Serrapeptase is a proteolytic enzyme isolated from the non-pathogenic bacteria Serratia species found in the digestive tract of the Japanese silkworm. The enzyme is used by the worms to digest their cocoons. Serrapeptase has been used as a nutritional supplement in Europe and Asia for nearly three decades. Each vegetarian capsule of Best Serrapeptase contains enteric-coated pure serrapeptase designed for optimal absorption in the intestinal tract. Note: Best Serrapeptase is quantified in "Serratiopeptidase units," which refers to the enzyme activity level. Enzymes like Serrapeptase are not measured in milligrams (mg), but in an unassociated measure of units. Best Serrapeptase has 40,000 Serratiopeptidase units per capsule, which is considered a very high amount of activity. Since Best High Potency Serrapeptase contains a tremendous 120,000 units, suggested use is only 1 capsule per day.