Superoxide Dismutase is an enzyme associated with metallic ions such as Copper, Zinc, Manganese, ect. This kind of metallic enzyme, especially those exists in human or animals's erythrocytes, has a strong activity and has a high value for nutrition, health and medicinal purposes. The main function of Superoxide Dismutase is anti-aging, it has been proved by scientists in the world.So SOD has been touted as the most powerful life-extending discovery of our time! Source: pig or bovine erythrocytes shape: A Dialyzed Lyophilized Powder We can offer Superoxide Dismutase (SOD) with very good price, activity:3000u/mg min, 2-3kg/month.