Science-Based Nutrition™Helps Support the Circulatory and Immune SystemDietary SupplementVegan / Non-GMO / Gluten FreeDoctor’s Best Natto-Serra is a combination of two natural enzymes that have been used as dietary supplements for decades. Serrapeptase (serratio-peptidase) is a protein-digesting enzyme isolated from the friendly bacterium Serratia E-15 discovered in the Japanese silkworm. Nattokinase also digests protein and is derived from “natto”, a fermented soy food popular in Japan for centuries. This nattokinase is free of vitamin K. The serrapeptase is formulated with Serrateric®, a superior alternative to enteric coating that protects the enzyme until it reaches the intestine for optimal absorption.Helps support the circulatory systemHelps support the immune system