Cat's claw is a woody vine native to the Amazon rainforest and other places in South East Asia. The common name of cat’s claw comes from the unique shape of the thorns, which look like the claws of a cat. The bark and root have been used for centuries to treat health problems including arthritis, stomach ulcers, inflammation, dysentery, and fevers. The studies indicate that cat's claw may stimulate the immune system, help relax the smooth muscles (such as the intestines), dilate blood vessels (helping lower blood pressure), and act as a diuretic (helping the body eliminate excess water.