What is it?
Cat’s claw has not been shown to be effective for cancer or AIDS.
Cat’s claw is a vine native to South America, the bark of which has been used in traditional medicine to treat various conditions such as gastric and inflammatory disorders. It is marketed as a dietary supplement to support the body’s natural defenses, for digestive and joint health, and as a general health tonic.
In lab experiments, compounds from cat’s claw stimulated specific immune cells known as phagocytes and T-helper cells. Other lab studies suggest cat’s claw may enhance DNA repair, or reduce inflammation and some chemotherapy side effects. However, one lab study showed it may actually stimulate pediatric leukemia cells.
Data in humans are limited, and studies on safety and effectiveness for any condition are needed.
What are the potential uses and benefits?
- To treat arthritis
A small study of a highly purified extract suggested modest benefit in patients with active rheumatoid arthritis, but larger well-designed studies are needed. - To reduce chemotherapy side effects
Small studies suggest cat’s claw may protect against abnormally low white blood cell counts in patients receiving certain cancer treatments. It may also improve quality of life in those with advanced cancer. However, additional studies are needed. - To treat cancer
Lab studies suggest cat’s claw might inhibit certain cancer cells, although one study suggests it may also stimulate pediatric leukemia cells. Human data are lacking. - To treat gastrointestinal disorders
Lab studies suggest cat’s claw may reduce inflammation, but this has not been studied in humans. - To treat HIV and AIDS
Lab studies suggest cat’s claw can stimulate specific immune cells, but human studies are needed.
What are the side effects?
- Nausea, diarrhea, stomach discomfort
Case reports
- Kidney failure in a patient with lupus
- Worsening movement in a patient with Parkinson’s disease
What else do I need to know?
Do Not Take if:
- You are taking warfarin or other blood thinners: Cat’s claw may increase bruising and bleeding risk. Clinical relevance is not known.
- You are taking antiretroviral drugs: Case reports have shown that cat’s claw increases serum concentrations of atazanavir, ritonavir, and saquinavir, and can therefore increase their side effects.
- You are taking CYP 3A4 or 2J2 substrate drugs: Cat’s claw may alter the effect of drugs metabolized by these enzymes. Clinical relevance is not known.
- You are taking UGT 1A3 or 1A9 substrate drugs: Cat’s claw may alter the effect of drugs metabolized by these enzymes. Clinical relevance is not known.