|| Uncaria tomentosaCommon name: Una de gato
Cat's claw (Uncaria tomentosa) is a woody vine native to the Amazon
rainforest and other tropical areas of South and Central America. Cat's claw is
named after the hook-like thorns that grow along its vine. The bark and root of
this herb have been used among indigenous people of the rainforest for centuries
to treat a variety of health problems including arthritis, ulcers, sexually
transmitted diseases, fevers, and even cancer. Some women consumed cat's claw as
a contraceptive because large doses of this herb were believed to cause
After these claims drew the attention of scientists in Europe, tests began to
demonstrate that substances in cat's claw boost the activity of the immune
system, reduce inflammation, scavenge damaging particles known as free radicals,
and destroy cancerous cells. Today, professional herbalists in the United States
and Europe recommend cat's claw to treat inflammatory disorders such as
arthritis, viral diseases such as HIV/AIDS, gastrointestinal illnesses such as
Crohn's disease, ulcers, and certain cancers. Despite the purported benefits
associated with cat's claw, relatively few scientific studies have investigated
the safety and usefulness of this herb.
In one study of 13 patients with human immunodeficiency virus (HIV) who
refused to take conventional treatments, a dosage of 20 mg cat's claw per day
for up to 5 months significantly increased white blood cell counts (the
infection-fighting cells in the body that HIV destroys). Cat's claw was also
found to boost white blood cell count in rats receiving chemotherapy. (A common
side effect of chemotherapy is low white blood cell count.) In another study of
45 people with osteoarthritis of the knee, those who received cat's claw
reported a significant reduction in knee pain compared to those who received
placebo. Further studies are needed to confirm these preliminary findings,
however. Another area that is being studied currently at Oregon Health Sciences
University is the use of cat's claw for Alzheimer's disease; no information is
available yet to indicate if the herb is helpful or harmful for this condition.
Cat's claw is a thorny vine that can climb as high as 100 feet. It is
primarily found in the Amazon rainforest as well as tropical areas in South and
Central America. Much of the cat's claw sold in the United States was grown in
Cat's claw got its name from the curved, claw-like thorns that grow on its
stem. The root and bark of cat's claw are the parts used for medicinal purposes.
|What's It Made Of?|
Cat's claw contains many types of plant chemicals that help reduce
inflammation (such as tannins and sterols) and combat certain viruses (such as
quinovic acid glycosides).
Cat's claw preparations are made from the root and bark of the of the cat's
claw vine. The effectiveness of the root and bark vary depending upon what time
of year that portion of the plant is harvested.
The bark of the cat's claw vine can be crushed and used to make tea.
Standardized root and bark extracts are also available in either liquid or dried
|How to Take It|
There are no known scientific reports on the pediatric use of cat's claw.
Therefore, it is not currently recommended for children.
- Tea: 1 gram (1,000 mg) root bark to 8 ounces water, boil 10 to 15
minutes, cool, and strain. Drink 1 cup three times daily.
- Tincture (solution made from herb and alcohol, or herb, alcohol, and
water): ¼ to ½ teaspoonful two to three times daily
- Dry, encapsulated standardized extract: 20 to 60 mg daily
The use of herbs is a time-honored approach to strengthening the body and
treating disease. Herbs, however, contain active substances that can trigger
side effects and that can interact with other herbs, supplements, or
medications. For these reasons, herbs should be taken with care, under the
supervision of a practitioner knowledgeable in the field of botanical
Although traditional lore indicates that cat's claw is very safe and
nontoxic, the American Herbal Products Association (AHPA) gives cat's claw a
class 4 safety rating which indicates a lack of scientific data to test that the
herb is actually safe. In addition, the AHPA does indicate that the tannin
content of cat's claw may cause some abdominal pain or gastrointestinal problems
including diarrhea. The diarrhea or loose stools tend to be mild and go away
with continued use of the herb.
Cat's claw should not be used by individuals with skin grafts or tuberculosis
or by those receiving organ transplants. It should not be used by pregnant or
breastfeeding women or by children who are under three years of age.
If you are currently being treated with any of the following medications, you
should not use cat's claw without first talking to your healthcare provider.
In theory, because cat's claw
may stimulate the immune system, this herb should not be used with medications
intended to suppress the immune system, such as cyclosporin or other medications
prescribed following an organ transplant. This theory has not been tested
Cat's claw may protect against gastrointestinal damage
associated with nonsteroidal anti-inflammatory drugs (NSAIDs), such as
Aquino R, De Feo V, De Simone F, Pizza C, Cirino G. New compounds and
anti-inflammatory activity of Uncaria tomentosa. J Nat Prod.
Blumenthal M, Riggins C. Popular Herbs in the U.S. Market: Therapeutic
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Foster S, Tyler VE. Tyler's Honest Herbal. 4th ed. New York: The
Haworth Herbal Press; 1999: 97-99.
Karch SB. The Consumer's Guide to Herbal Medicine. Hauppauge, New
York: Advanced Research Press; 1999:55-56.
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.
Lemaire I, Assinewe V, Cano P, Awang DV, Arnason JV. Stimulation of
interleukin-1 and -6 production in alveolar macrophages by the neotropical
liana, Uncaria tomentosa. J Ethnopharmacol.
Piscoya J, Rodriguez Z, Bustamante SA, Okuhama NN, Miller MJ, Sandoval M.
Efficacy and safety of freeze-dried cat's claw in osteoarthritis of the knee:
mechanisms of action of the species Uncaria guianensis. Inflamm
Rizzi R, Re F, Bianchi A, De Feo V, de Simone F, Bianchi L, Stivala LA.
Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts.
J Ethnopharmacol. 1993;38(1):63-77.
Rotblatt M, Ziment I. Evidence-Based Herbal Medicine. Philadelphia,
PA: Hanley & Belfus, Inc; 2002:114-118.
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.
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.
Sheng Y, Pero RW, Wagner H. Treatment of chemotherapy-induced leukopenia in a
rat model with aqueous extract from Uncaria tomentosa. Phytomedicine.
Steinberg PN. Cat's claw: medicinal properties of this Amazon vine.
Nutrition Science News. 1995.
|Review Date: April 2002|
|Reviewed By: Participants in the review process include: Shiva Barton, ND (April 1999),
Wellspace, Cambridge, MA; Jacqueline A. Hart, MD, Department of Internal
Medicine, Newton-Wellesley Hospital, Harvard University and Senior Medical
Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh (Pediatric Dosing
section February 2001), Johnson Drugs, Natick, MA; Steven Ottariono, RPh,
Veteran's Administrative Hospital, Londonderry, NH; David Winston, Herbalist
(April 1999), Herbalist and Alchemist, Inc., Washington, NJ; Tom Wolfe, P.AHG
(April 1999), Smile Herb Shop, College Park, MD. All interaction sections have
also been reviewed by a team of experts including Joseph Lamb, MD (July 2000),
The Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh (August
2000), Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in Pharmacy
(March 2000), Clinical Assistant Professor, University of Maryland School of
Pharmacy; President, Your Prescription for Health, Owings Mills, MD; R. Lynn
Shumake, PD (March 2000), Director, Alternative Medicine Apothecary, Blue
Mountain Apothecary & Healing Arts, University of Maryland Medical Center,
Glenwood, MD; Ira Zunin, MD, MPH, MBA (July 2000), President and Chairman,
Hawaii State Consortium for Integrative Medicine, Honolulu,
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