Cat's claw contains chemicals called oxindole alkaloids. A researcher named Klaus Keplinger patented some of these based on evidence that they affect immune function. However, a patent is not the same thing as approval by the Food and Drug Administration. Other research showed that cat's claw also contains different kinds of alkaloids that affect the central nervous system. These alkaloids might work against the alkaloids that affect the immune system.
More research is needed.
Peruvian natives use cat's claw to treat inflammatory diseases like arthritis, to clean out the digestive tract and to treat cancer. It has also been used to treat dysentery, recovery from childbirth, and women's hormone imbalances. In laboratory studies, cat's claw normalizes some immune system functions. It also appears to help reduce blood clotting. We do not know if these laboratory results will carry over to studies in people.