Cat’s claw—or uña de gato in Spanish—is a large, woody vine native to tropical rain forests in Central and South America. The liana has long, claw-like thorns that allow it to climb more than 100 feet into the tree canopy. Because of this, cat’s claw is not easily cultivated, and only the stem bark is used to protect the species.

Indigenous healers have used cat’s claw bark for centuries to promote healing and treat intestinal distress. The herbal medicine was essentially unknown outside of Amazonia before the 1970s. Today, cat’s claw bark is used to support the immune system. The plant has anti-inflammatory properties for treating joint problems, and as an antioxidant, cat’s claw is being studied as a potential cancer treatment.

Cat’s claw bark powder may be used for teas, tinctures, extracts and encapsulation. The cut and sifted bark is also available. Because of possible effects on the immune system, cat’s claw should not be used by those with autoimmune conditions or taking immunosuppressive or blood pressure medications.