Sustainably Harvested Cat's Claw Extract that Enhances Natural Immunity. Saventaro is a standardized extract free of harmful levels of certain substances called tetracyclic oxindole alkaloids (or "TOAs") commonly found in traditional cat's claw extracts. . Saventaro is the only patented clinically studied and guaranteed cat's claw extract to benefit both the natural and acquired immune systems. . Saventaro provides beneficial compounds that support the body's natural anti-inflammatory response. By modifying the immune system Saventaro can help support a healthy range of motion.