Herbs & Supplements:
Cat's Claw
Uncaria tomentosa
Principal Proposed Uses
•
Osteoarthritis
•
VARIOUS VIRAL DISEASES:
Genital and Oral Herpes, Shingles (Herpes Zoster), AIDS, Feline Leukemia Virus
Other Proposed Uses
•
Allergies, Arthritis, Ulcers
Cat's claw is a popular herb among the indigenous people of Peru, where it is used to treat cancer, diabetes, ulcers, arthritis, and infections, as well as assist in recovery from childbirth. It is also used as a contraceptive.
One double-blind, placebo-controlled study suggests that cat's claw may be helpful for the treatment of osteoarthritis. There are many other proposed uses of cat's claw, but they all lack meaningful scientific substantiation.
What Is Cat's Claw Used for Today?
Cat's claw is most often marketed as a treatment for viral diseases such as herpes, shingles, AIDS, and feline leukemia virus. However, the evidence for these uses is extremely preliminary.
The most meaningful study yet performed on cat's claw suggests that it might be helpful for an entirely different condition: osteoarthritis.3
Cat's claw has also been proposed as a treatment for allergies, stomach ulcers and rheumatoid arthritis, but there is no meaningful evidence as yet that it is effective for these conditions.
What Is the Scientific Evidence for Cat's Claw?
A four week, double-blind, placebo-controlled trial evaluated the potential benefits of cat’s claw for the treatment of osteoarthritis.3 A total of 45 individuals with osteoarthritis were enrolled. Of these, 30 were treated with freeze dried cat’s claw aqueous extract, and 15 were given placebo. Individuals in the treatment group showed reduced pain with activity as compared to those in the placebo group. However, no comparative improvements were seen in knee pain at rest or at night, nor in knee circumference.
This pilot trial suggests that cat’s claw may be a useful treatment for osteoarthritis. However, more research will be necessary to verify this potential use of the herb.
Dosage
The optimum dosage of cat's claw is not clear. Because of the wide variation in the forms and preparations sold, we recommend following the directions on the product's label.
Safety Issues
In general, use of cat’s claw has not been associated with adverse effects more serious than occasional digestive upset or allergic reactions. However, full safety studies have not been completed, and there has been one report of kidney failure apparently triggered by cat's claw.4
Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.
Some evidence suggests that cat's claw might interact with various medications by affecting their metabolism in the liver, but the extent of this effect has not been fully determined.2
View References
Last reviewed May 2002 by Medical Review Board
Back to Top
