Cat’s claw grows in the rain forests of the Andes Mountains in South America, particularly in Peru. The two species of the plant used most commonly are U. tomentosa, which makes up most of the cat’s claw imported to the U.S., and U. guianensis, which is more widely used in Europe. In South America, both species are used interchangeably. The root bark is used as medicine.
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3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
100 mg of a freeze-dried preparation daily
Cat’s claw has been used traditionally for osteoarthritis. In one trial, cat's claw was significantly more effective than a placebo at relieving pain and improving overall condition.
Cat’s claw has been used traditionally for osteoarthritis. In a double-blind trial, 100 mg per day of a freeze-dried preparation of cat's claw taken for four weeks was significantly more effective than a placebo at relieving pain and improving the overall condition.2
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Cat’s claw has been used traditionally to treat rheumatoid arthritis.
In a double-blind trial, supplementation with an extract from cat's claw (Uncaria tomentosa) for 24 weeks was significantly more effective than a placebo in reducing the number of painful joints in patients with rheumatoid arthritis. The amount used was 20 mg of extract three times per day. The extract was obtained from a specific strain of cat's claw that contains pentacyclic oxindole alkaloids, compounds that appear to influence the activity of the immune system. The extract was purified to be free of tetracyclic oxindole alkaloids, which may inhibit the beneficial effects of the other alkaloids.3
HIV and AIDS Support
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Cat’s claw is an immuno-modulating herb. Standardized extracts of it have been shown to help prevent CD4 cell counts from dropping and to prevent opportunistic infections.
Cat’s claw is another immuno-modulating herb. Standardized extracts of cat’s claw have been tested in small, preliminary trials in people infected with HIV, showing some benefits in preventing CD4 cell counts from dropping and in preventing opportunistic infections.4 , 5 Further study is needed to determine whether cat’s claw is truly beneficial for people with HIV infection or AIDS.
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Substances found in cat’s claw, called oxyindole alkaloids, have been shown to stimulate the immune system.
Substances found in cat’s claw, called oxyindole alkaloids have been shown to stimulate the immune system.6 However, little is known about whether this effect is sufficient to prevent or treat disease.
Cat’s claw has been reportedly used by indigenous peoples in the Andes to treat inflammation, rheumatism, gastric ulcers, tumors, dysentery, and as birth control.1 Cat’s claw is popular in South American folk medicine for treating intestinal complaints, gastric ulcers, arthritis, and to promote wound healing.
According to test tube studies, oxyindole alkaloids in cat’s claw stimulate immune function.7 Alkaloids and glycosides in cat’s claw have also demonstrated anti-inflammatory and antioxidant activity.8 , 9
Although clinical trials are lacking, cat’s claw has become very popular in North America and is sometimes recommended for people with cancer or HIV infection. A cigarette smoker who took a freeze-dried extract of cat’s claw root bark for one month showed a sharp decrease in one urinary cancer marker.10 This finding, however, does little to support the use of the herb in persons with cancer and points toward the need for actual clinical studies to determine its effectiveness.
In a study of patients with osteoarthritis, 100 mg per day of a freeze-dried preparation was used. Cat’s claw tea is prepared from 1/4 teaspoon (1 gram) of root bark by adding 1 cup (250 ml) of water and boiling for ten to fifteen minutes. Cool, strain and drink one cup three times per day. Alternatively, 1/4–1/2 teaspoon (1–2 ml) of tincture can be taken up to two times per day, or 20–60 mg of a dry standardized extract can be taken once per day.13
Although no serious adverse effects have been reported for cat’s claw, there is little known about its safety because most reports have been based on anecdotal evidence. There is one case report in which Parkinson's disease became worse after a man started using cat's claw and improved after cat's claw was discontinued.14 Cat’s claw should be used with caution in people with autoimmune illness, multiple sclerosis, and tuberculosis. Until proven safe, cat’s claw should not be taken by pregnant or breast-feeding women.
1. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 18-9.
2. 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;50:442-8.
3. Mur E, Hartig F, Eibl G, Schirmer M. Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of Uncaria tomentosa for the treatment of rheumatoid arthritis. J Rheumatol 2002;29:678-81.
4. Keplinger UM. Influence of Krallendorn extract on retroviral infection. Zürcher AIDS Kongress Zurich, Switzerland, Oct 16-7, 1992 [abstract in German].
5. Keplinger UM. Therapy of HIV-infected individuals in the pathological categories CDC A1 and CDC B2 with a preparation containing IMM-207. IV. Österreichischer AIDS-Kongress, Vienna, Austria, Sept 17-8, 1993, 45 [abstract].
6. Keplinger H. Oxindole alkaloids having properties stimulating the immunologic system and preparation containing same. US Patent no. 5,302,611, April 12, 1994.
7. Keplinger H. Oxindole alkaloids having properties stimulating the immunologic system and preparation containing same. US Patent no. 5,302,611, April 12, 1994.
8. Aquino R, De Feo V, De Simone F, et al. Plant metabolites, new compounds and anti-inflammatory activity of Uncaria tomentosa. J Nat Prod 1991;54:453-9.
9. Rizzi R, Re F, Bianchi A, et al. Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts. J Ethnopharmacol 1993;38:63-77.
10. Rizzi R, Re F, Bianchi A, et al. Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts. J Ethnopharmacol 1993;38:63-77.
11. 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;50:442-8.
12. Mur E, Hartig F, Eibl G, Schirmer M. Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of Uncaria tomentosa for the treatment of rheumatoid arthritis. J Rheumatol 2002;29:678-81.
13. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 18-9.
14. Cosentino C, Torres L. Reversible worsening of Parkinson's disease motor symptoms after oral intake of Uncaria tomentosa (cat's claw). Clin Neuropharmacol 2008;31:293-4.
Last Review: 07-08-2014
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