Cat's Claw

Botanical Name(s):

Uncaria tomentosa Family: Rubiaceae

Other Name(s):

una de gato

General Description:

Cat's claw is a climbing vine that grows in the high Peruvian tropical forests. Two species, Uncaria tomentosa and Uncaria guianensis, have traditionally been used by the Peruvian Indians to treat arthritis, digestive problems and other ailments. The active ingredients are extracted from the bark and root of the vine. Both types of Uncaria are being evaluated by modern research methods and have been shown to be effective as both an anti-inflammatory and an immune stimulant.

Cats claw is normally taken as a bark decoction (boiling a specific amount of herb in water) and contains different alkaloids (including rhynchophylline and isorhynchophyllin) that have immune stimulating, anti-hypertensive, diuretic and smooth-muscle relaxant effects.

Medically Valid Uses:

Currently, there are no rigorously established uses for cat's claw.

Unsubstantiated Claims:

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Evidence indicates that cat's claw is useful for treating certain digestive disturbances. For instance, it may protect the lining of the small intestine from damage done by anti-inflammatory agents such as indomethacin. In addition, pentacyclic oxindole alkaloids found in cat's claw are claimed to modulate the immune system by increasing the activity of white blood cells and increasing the levels of Interleukin-1.

Some claims suggest that cat's claw helps cleanse the intestinal tract and treat some viral infections. Cat's claw is also claimed to have antioxidant, anti-mutagenic (preventing mutation) and anti-inflammatory properties. Other claims even suggest that cat's claw may play a role in treating AIDS and cancer, as well as arthritis and ulcers.

Dosing Format:

Cat's claw comes in tablets and capsules. Follow packaging instructions for correct dose.

Side Effects, Toxicity and Interactions:

Few side effects are associated with this herbal remedy. Toxicity studies have shown that cat's claw is non-toxic at standard dosing levels. At higher doses, cat's claw is toxic to the kidneys.

Women who are pregnant or breast-feeding should not use cat's claw.

There are no known significant food or drug interactions. In general, alkaloids are absorbed better in an acid environment, so cat's claw should not be taken with antacids.

Additional Information:

Click here for a list of reputable Web sites with general information on nutrition.


  1. Santa Maria A, Lopez A, Diaz MM, et al. Evaluation of the toxicity of Uncaria tomentosa by bioassays in vitro. J Ethnopharmacol. 1997;57(3):183-7.

  2. Sandoval-Chacon M, Thompson JH, Zhang XJ, et al. Antiinflammatory actions of cat's claw: the role of NF-kappaB. Aliment Pharmacol Ther. 1998;12(12):1279-89.

  3. Keplinger K, Laus G, Wurm M, Dierich MP, Teppner H. Uncaria tomentosa (Willd.) DC.--ethnomedicinal use and new pharmacological, toxicological and botanical results. J Ethnopharmacol. 1999;64(1):23-34.

  4. Lemaire I, Assinewe V, Cano P, Awang DV, Arnason JT. Stimulation of interleukin-1 and -6 production in alveolar macrophages by the neotropical liana, Uncaria tomentosa (una de gato). J Ethnopharmacol. 1999;64(2):109-15.

  5. Reinhard KH. Uncaria tomentosa (Willd.) D.C.: cat's claw, una de gato, or saventaro [In Process Citation]. J Altern Complement Med. 1999;5(2):143-51.

  6. Aquino R, De Simone F, Pizza C, Conti C, Stein ML. Plant metabolites. Structure and in vitro antiviral activity of quinovic acid glycosides from Uncaria tomentosa and Guettarda platypoda. J Nat Prod. 1989;52(4):679-85.

  7. Rizzi R, Re F, Bianchi A, et al. Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts. J Ethnopharmacol. 1993;38(1):63-77.

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