From the Manufacturer:
Uña de Gato (Cat’s Claw) [Immune] is a remarkable tonic herb and is now considered equal, if not superior, to the world’s foremost immune-fortifying herbs: echinacea, golden seal, pau d’arco, garlic and eleuthero. It has also been compared favorably with shark cartilage and caprylic acid. It is particularly beneficial to the immune, digestive and structural systems.
The inner bark of this vine provides beneficial alkaloids.