This amazing rainforest vine has become quite popular in the U.S. for it's patented ability to boost immune function. Some of the active ingredients documented and researched in Cat's Claw are 6 oxindole alkaloids. These alkaloids have been documented worldwide by independent research and patented to nutritionally support the immune system.

Raintree's Cat's Claw has the highest alkaloid content
of any standard inner bark capsules available.

Total alkaloid content of tested samples from other available products range from .13% to 1.05%. This represents a huge difference in quality and efficacy. Because of commitment to quality, Raintree's alkaloid content has always assayed in a range of 1.2% to 1.58%. Compare this to the new "standardized extract" offered in health food stores with only 2 milligrams of alkaloids per capsule at a much higher price! 

For more complete information on this unique rainforest plant, please see the Plant Database File on Cat's Claw.

Our Cat's Claw has been sustainably wild harvested in the Peruvian Amazon. It has grown naturally in the rainforest without pesticides or fertilizers. This plant is non-irradiated and non-fumigated. To learn more about Raintree's plant harvesting and processing methods, please click here

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Traditional Uses: As an immune stimulant and an adjunctive therapy for cancer (to reduce side effects of chemotherapy and protect cells); as a bowel cleanser and anti-inflammatory for Crohn's, colitis, diverticulitis, irritable bowel syndrome (IBS), and other bowel problems; as an anti-inflammatory for arthritis (all kinds) and muscle pains/strains/injuries; as a general daily tonic (to tone, balance, and strengthen all body functions); for stomach ulcers and ulcerative colitis and as an ulcer preventative/stomach and bowel protector)

Ingredients: Each capsule contains 500 mg of pure 100% cat's claw inner vine bark (Uncaria tomentosa). No binders, fillers or other additives are used.

Suggested Use: Take 2 capsules twice daily, or as directed by a healthcare professional.

Contraindications

• Cat's claw has been documented with immunostimulant effects and is contraindicated before or following any organ or bone marrow transplant or skin graft.
• Cat's claw has been documented with antifertility properties and is contraindicated in persons seeking to get pregnant.
• Cat's claw has been documented with chemicals which can reduce platelet aggregation and thin the blood. It is contraindicated in persons with bleeding disorders such as hemophilia.

Drug Interactions: Based upon animals studies, cat's claw may protect against gastrointestinal damage associated with NSAIDs such as ibuprofen. May potentiate coumadin and blood-thinning drugs.

Other Practitioner Observations

• Cat's claw requires sufficient stomach acid to help break down the tannins and alkaloids during digestion and to aid in absorption. Avoid taking capsules at the same time as antacids.
• Large dosages of cat's claw (3-4 gram dosages) have been reported to cause some abdominal pain or gastrointestinal problems including diarrhea (due to the tannin content of the vine bark). The diarrhea or loose stools tend to be mild and go away with continued use. Discontinue use or reduce dosage if diarrhea persists longer than 3-4 days. 

Print a FREE Technical Data Report (normally sells for US$20.00) 

Third-Party Published Research
This Raintree product has not been the subject of any clinical research. All available third-party research on cat's claw can be found at PubMed/Medline. A partial listing of the published research on cat's claw is shown below:

Immunostimulant & Immunomodulatory Actions:
Spelman, K., et al. "Modulation of cytokine expression by traditional medicines: a review of herbal immunomodulators." Altern. Med. Rev. 2006 Jun; 11(2): 128-50.
Eberlin, S., et al. “Uncaria tomentosa extract increases the number of myeloid progenitor cells in the bone marrow of mice infected with Listeria monocytogenes.” Int. Immunopharmacol. 2005; 5(7-8):1235-46.
Deharo, E., et al. ”In vitro immunomodulatory activity of plants used by the Tacana ethnic group in Bolivia.” Phytomedicine. 2004 Sep; 11(6): 516-22.
Lamm, S., et al, “Persistent response to pneumococcal vaccine in individuals supplemented with a novel water soluble extract of Uncaria tomentosa, C-Med-100." Phytomedicine. 2001; 8(4): 267–74.
Sheng Y, et al., “Treatment of chemotherapy-induced leukopenia in a rat model with aqueous extract from Uncaria tomentosa.” Phytomedicine. 2000; 7(2): 137–43.
Lemaire, I., et al. “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.
Marina, M. D. “Evaluacion de la actividal immunoestimulante de Uncaria tomentosa (Willd.) DC. Una de gato en ratones albinos." Biodiversidad Salud. 1998; 1(1): 16–19.
Keplinger, H., et al. “Oxindole alkaloids having properties stimulating the immunologic system and preparation containing same.” United States patent 5,302,611; April 12, 1994
Wagner, H., et al. “Die Alkaloide von Uncaria tomentosa und ihre Phagozytose-steigernde Wirkung." Planta Med. 1985; 51: 419–23.
Hemingway, S. R. and J. D. Phillipson. “Alkaloids from South American species of Uncaria (Rubiaceae)." J. Pharm. Pharmacol. 1974 suppl.; 26: 113p.

Anti-inflammatory Actions:
Hardin, S. R. "Cat's claw: An Amazonian vine decreases inflammation in osteoarthritis." Complement. Ther. Clin. Pract. 2007 Feb; 13(1): 25-8.
Allen-Hall, L., et al. "Treatment of THP-1 cells with Uncaria tomentosa extracts differentially regulates the expression if IL-1beta and TNF-alpha." J. Ethnopharmacol. 2007 Jan; 109(2): 312-7.
Miller, M. J., et al. "The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1beta." BMC Complement. Altern. Med. 2006 Apr; 6: 13.
Miller, M. J., et al. "Early relief of osteoarthritis symptoms with a natural mineral supplement and a herbomineral combination: a randomized controlled trial [ISRCTN38432711]." J. Inflamm. 2005 Oct; 2:11.
Valerio, L. G., et al. "Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii): a critical synopsis." Toxicol. Rev. 2005; 24(1): 11-35.
Setty, A. R., et al. "Herbal medications commonly used in the practice of rheumatology: mechanisms of action, efficacy, and side effects." Semin. Arthritis Rheum. 2005; 34(6): 773-84.
Sheng, Y., et al. “An active ingredient of Cat's Claw water extracts: identification and efficacy of quinic acid.” J. Ethnopharmacol. 2005 Jan 15; 96(3):
Aguilar, J. L., et al. “Anti-inflammatory activity of two different extracts of Uncaria tomentosa (Rubiaceae).” J. Ethnopharmacol. 2002; 81(2): 271–76.
Sandoval, M., et al., “Anti-inflammatory and antioxidant activities of cat’s claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content." Phytomedicine. 2002; 9(4): 325–37.
Mur, E., et al. “Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of Uncaria tomentosa for the treatment of rheumatoid arthritis.” J. Rheumatol. 2002 Apr; 29(4): 678–81.
Sandoval-Chacon, M., et al. “Anti-inflammatory actions of cat’s claw: the role of NF-kappaB.” Aliment. Pharmacol. Ther. 1998; 12(12): 1279–89.
Recio, M. C., et al. “Structural requirements for the anti-inflammatory activity of natural triterpenoids.” Planta Med. 1995; 61(2): 182–85.
Aquino, R., et al. “Plant metabolites. New compounds and anti-inflammatory activity of Uncaria tomentosa." J. Nat. Prod. 1991; 54: 453–59.
Cerri, R., et al. “New quinovic acid glycosides from Uncaria tomentosa." J. Nat. Prod. 1988; 51: 257–61.

Anticancerous & Antitumor Actions:
Gonzales, G.F., et al. "Medicinal plants from Peru: a review of plants as potential agents against cancer." Anticancer Agents Med. Chem. 2006 Sep; 6(5): 429-44.
De Martino, L., et al. "Proapoptotic effect of Uncaria tomentosa extracts." J. Ethnopharmacol. 2006 Aug; 107(1): 91-4.
Bacher, N., et al. "Oxindole alkaloids from Uncaria tomentosa induce apoptosis in proliferating, G0/G1-arrested and bcl-2-expressing acute lymphoblastic leukaemia cells." Br. J. Haematol. 2006 Mar; 132(5): 615-22.
Riva, L., et al. “The antiproliferative effects of Uncaria tomentosa extracts and fractions on the growth of breast cancer cell line." Anticancer Res. 2001; 21(4A): 2457–61.
Muhammad, I., et al. “Investigation of Una de Gato I. 7-Deoxyloganic acid and 15N NMR spectroscopic studies on pentacyclic oxindole alkaloids from Uncaria tomentosa." Phytochemistry. 2001; 57(5): 781–5.
Sheng, Y., et al. “Induction of apoptosis and inhibition of proliferation in human tumor cells treated with extracts of Uncaria tomentosa." Anticancer Res. 1998; 18(5A): 3363–68.
Salazar, E. L., et al. “Depletion of specific binding sites for estrogen receptor by Uncaria tomentosa." Proc. West. Pharmacol. Soc. 1998; 41(1): 123–124.
Stuppner, H., et al. “A differential sensitivity of oxindole alkaloids to normal and leukemic cell lines.” Planta Med. (1993 suppl.); 59: A583.
Rizzi, R., et al. “Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts." J. Ethnopharmacol. 1993; 38: 63–77.
Peluso, G., et al. “Effetto antiproliferativo su cellule tumorali di estrattie metaboliti da Uncaria tomentosa. Studi in vitro sulla loro azione DNA polimerasi.” 11 Congreso Italo-Peruano de Etnomedicina Andina, Lima, Peru, October 27–30, 1993, 21–2.
Rizzi, R., et al. “Bacterial cytotoxicity, mutagenicity and antimutagenicity of Uncaria tomentosa and its extracts. Antimutagenic activity of Uncaria tomentosa in humans." Premiere Colloque Européan d'Ethnopharmacologie, Metz, France, March 22–24, 1990.

Cellular Protective & Antioxidant Actions:
Mammone, T., et al. "A water soluble extract from Uncaria tomentosa (Cat's Claw) is a potent enhancer of DNA repair in primary organ cultures of human skin." Phytother. Res. 2006; 20(3): 178-83.
Kuras, M., et al. "Changes in chromosome structure, mitotic activity and nuclear DNA content from cells of Allium Test induced by bark water extract of Uncaria tomentosa (Willd.) DC." J. Ethnopharmacol. 2006 Sep; 107(2):211-21.
Pilarski, R., et al. "Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC." J. Ethnopharmacol. 2006 Mar; 104(1-2): 18-23.
Cisneros, F. J., et al. “An Uncaria tomentosa (cat's claw) extract protects mice against ozone-induced lung inflammation.” J. Ethnopharmacol. 2005 Jan; 96(3): 355-64.
Goncalves, C., et al. “Antioxidant properties of proanthocyanidins of Uncaria tomentosa bark decoction: a mechanism for anti-inflammatory activity.” Phytochemistry. 2005; 66(1): 89-98.
Romero-Jimenez, M., et al. “Genotoxicity and anti-genotoxicity of some traditional medicinal herbs.” Mutat. Res. 2005 Aug; 585(1-2): 147-55.
Pilarski, R., et al. “Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC.” J. Ethnopharmacol. 2005 Sep 29;
Sheng, Y., et al. “DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study." Phytomedicine. 2001; 8(4): 275–82.
Sheng, Y., et al. “Enhanced DNA repair, immune function and reduced toxicity of C-Med-100, a novel aqueous extract from Uncaria tomentosa." J. Ethnopharmacol. 2000; 69(2): 115–26.
Sandoval, M., et al. “Cat’s claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection.” Free Radic. Biol. Med. 2000; 29(1): 71–8.
Desmarchelier, C., et al. “Evaluation of the in vitro antioxidant activity in extracts of Uncaria tomentosa (Willd.) DC." Phytother. Res. 1997; 11(3): 254–256.
Chan-Xun, C., et al. “Inhibitory effect of rhynchophylline on platelet aggregation and thrombosis.” Acta Pharmacologica Sinica 1992; 13(2): 126–30.

Actions on the Brain and Memory:
Jurgensen, S., et al. “Involvement of 5-HT2 receptors in the antinociceptive effect of Uncaria tomentosa.” Pharmacol. Biochem. Behav. 2005 Jul; 81(3): 466-77.
Kang, T. H., et al. “Pteropodine and isopteropodine positively modulate the function of rat muscarinic M(1) and 5-HT(2) receptors expressed in Xenopus oocyte.” Eur. J. Pharmacol. 2002 May; 444(1-2): 39-45.
Mohamed, A. F., et al. “ Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test.” J. Pharm. Pharmacol. 2001; 52(12): 1553–61.
Roth, B. L., et al. “Insights into the structure and function of 5-HT(2) family serotonin receptors reveal novel strategies for therapeutic target development.” Expert Opin. Ther. Targets 2001 Dec; 5(6): 685-695.
Castillo, G. "Methods of isolation of amyloid inhibitory ingredients within Uncaria tomentosa." US Patent No 7,029,710, April, 18, 2006.
Castillo, G. " Methods of isolating amyloid-inhibiting compounds and use of compounds isolated from Uncaria tomentosa and related plants." US Patent No. 6,929,808, August 16, 2005.
Castillo, G., et al. “Pharmaceutical compositions containing Uncaria tomentosa extract for treating Alzheimer's disease and other amyloidoses." Patent-Pct. Int. Paol. 1998; 00 33,659: 67pp.

Antimicrobial Actions:
Kloucek, P., et al. “Antibacterial screening of some Peruvian medicinal plants used in Calleria District.” J. Ethnopharmacol. 2005 Jun; 99(2): 309-12.
Garcia, R., et al. “Antimicrobial activity of isopteropodine.” Z. Naturforsch. 2005; 60(5-6): 385-8.
Aquino, R., et al. “Plant metabolites. Structure and in vitro antiviral activity of quinovic acid glycosides from Uncaria tomentosa and Guettarda platypoda." J. Nat. Prod. 1989; 4(52): 679–85.