Cat's claw is a tropical vine that grows in rainforest and jungle areas in South America and Asia. Some cultures refer to the plant as the "Sacred Herb of the Rain Forest". This vine gets its name from the small thorns at the base of the leaves, which looks like a cat's claw. These claws enable the vine to attach itself around trees climbing to a heights up to 100 feet. The plant is considered a valuable medicinal resource and is protected in Peru. Although scientific research has just recently begun to explore cat's claw, many cultures native to the South American rain forest areas have used this herb for hundreds of years. Preliminary studies have demonstrated very little potential benefit with Cat's claw in the treatment of cancer. Although no serious adverse effects have been reported, there is little known about its safety because most reports have been based on anecdotal evidence. Until proven safe, cat’s claw should not be taken by pregnant or breast-feeding women. Also, there are no well-known drug interactions with cat’s claw.

Cat’s claw tea is prepared by combining 1/4 teaspoon (1 gram) of root bark and 1 cup (250 ml) of water and boiling for 10-15 minutes. Drink one cup tid. Cat's claw tincture at 1/4-1/2 teaspoon (1–2 ml) can be taken up to two times per day, or 20-60mg of a dry standardized extract can be taken once per day.