Cat's claw | University of Maryland Medical Center
Speak to your health care provider regarding dosing instructions.
Precautions
The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects, and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.
Cat's claw appears to have few side effects, however, there have not been enough scientific studies on cat's claw to determine its safety. Some people have reported dizziness, nausea, and diarrhea when taking cat's claw. The diarrhea or loose stools tend to be mild and go away with continued use of the herb.
Pregnant or nursing women should not take cat's claw because it may cause miscarriage.
People with autoimmune diseases, skin grafts, tuberculosis, or those receiving organ transplants should not use cat's claw unless specifically directed by their physician because of its possible effects on the immune system.
People with leukemia or low blood pressure should not take cat's claw.
People with kidney or liver disease should not use cat's claw without first asking their doctor.
Possible Interactions
If you are currently taking any of the following medications, you should not use cat's claw without first talking to your health care provider.
Medications that suppress the immune system: In theory, because cat's claw may stimulate the immune system, it should not be used with medications that suppress the immune system. Those include cyclosporine or other medications prescribed following an organ transplant, or to treat an autoimmune disease.
Blood-thinning medications: Cat's claw may increase the risk of bleeding, especially if you also take blood thinners such as aspirin, warfarin (Coumadin), or clopidogrel (Plavix).
Diuretics (water pills): Cat's claw may act as a diuretic, helping the body eliminate excess fluid. If you also take diuretics, which do the same thing, you could be at risk of developing an electrolyte imbalance.
Blood pressure medication: Cat's claw may lower blood pressure. If you take medication for high blood pressure, taking cat's claw may cause your blood pressure to be too low.
Other medications: Cat's claw may interfere with some medications that are processed by the liver. If you take any medications, check with your doctor before taking cat's claw.
Supporting Research
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de Fatima Fernandes Vattimo M, da Silva NO. Uncaria tomentosa and acute ischemic kidney injury in rats. Rev Esc Enferm USP. 2011;45(1):194-8.
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Hardin SR. Cat's claw: an Amazonian vine decreases inflammation in osteoarthritis. Complement Ther Clin Pract. 2007 Feb;13(1):25-8.
Kaiser S, Dietrich F, de Resende PE, et al. Cat's claw oxindole alkaloid isomerization induced by cell incubation and cytotoxic activity against T24 and RT4 human bladder cancer cell lines. Planta Med. 2013;79(15):1413-20.
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Miller MJ, Mehta K, Kunte S, Raut V, Gala J, et al. Early relief of osteoarthritis symptoms with a natural mineral supplement and a herbomineral combination: a randomized controlled trial [ISRCTN38432711]. J Inflamm (Lond). 2005 Oct 21;2:11.
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Pilarski R, Zielinski H, Ciesiolka D, et al. Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC. J Ethnopharmacol. 2006 Mar 8;104(1-2):18-23.
Piscoya J, Rodriguez Z, Bustamante SA, et al. Efficacy and safety of freeze-dried cat's claw in osteoarthritis of the knee: mechanisms of action of the species Uncaria guianensis. Inflamm Res. 2001;50(9):442-448.
Quilez AM, Saenz MT, Garcia MD. Uncaria tomentosa (Willd. ex. Roem. & Schult.) DC. and Eucalyptus globulus Labill. interactions when administered with diazepam. Phytother Res. 2012;26(3):458-61.
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.
Rosenbaum CC, O'Mathúna DP, Chavez M, Shields K. Antioxidants and antiinflammatory dietary supplements for osteoarthritis and rheumatoid arthritis. Altern Ther Health Med. 2010 Mar-Apr;16(2):32-40. Review.
Sandoval M, Charbonnet RM, Okuhama NN, et al. Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection. Free Radic Biol Med. 2000;29(1):71-78.
Setty AR, Sigal LH. Herbal medications commonly used in the practice of rheumatology: mechanisms of action, efficacy, and side effects. Semin Arthritis Rheum. 2005 Jun;34(6):773-84. Review.
Sheng Y, et al. Induction of apoptosis and inhibition of proliferation in human tumor cells treated with extracts of Uncaria tomentosa. Anticancer Res. 1998;18:3,363-3,368.
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Spelman K, Burns J, Nichols D, et al. Modulation of cytokine expression by traditional medicines: a review of herbal immunomodulators. Altern Med Rev. 2006 Jun;11(2):128-50. Review.
Steinberg PN. Cat's claw: medicinal properties of this Amazon vine. Nutrition Science News. 1995.
Alternative Names