From the Manufacturer:
Prima Uña de Gato contains cat's claw (Uncaria tomentosa) extract standardized to a minimum of 0.5% pentacyclic oxindole alkaloids (POAs), and is 100% free of tetracyclic oxindole alkaloids (TOAs). The active POAs have been shown to affect the immune cells responsible for nonspecific and cellular immunity. Prima Uña de Gato also contains quinovic acid glycosides, the natural compounds upon which synthetic quinolones are based. Cat's claw is also known to help promote systemic microbial balance, and support antioxidant activity and circulation. Prima Uña de Gato contains added minerals and enzymes to enhance absorption and activity.