Botanical name: Uncaria tomentosa
© Steven Foster
Parts used and where grown
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.
Cat’s claw has been
used in connection with the following conditions (refer to the
individual health concern for complete information):
Historical or traditional use (may
or may not be supported by scientific studies)
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.
Active constituents
According to test tube studies, oxyindole alkaloids in cat’s claw stimulate immune function.2 Alkaloids and glycosides
in cat’s claw have also demonstrated anti-inflammatory and antioxidant
activity.3 4
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.5 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.
Cat’s claw has been used traditionally for osteoarthritis and rheumatoid arthritis. 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.6
How much is usually taken?
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.7
Are there any side effects or interactions?
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.
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.
At the time of writing, there were no well-known drug interactions
with cat’s claw.
References:1. Foster S. Herbs for Your Health. Loveland, CO: Interweave
Press, 1996, 18–9.
2. Keplinger H. Oxyindole alkaloids having properties stimulating the
immunologic system and preparation containing same. US Patent no. 5,302,611, April 12,
1994.
3. 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.
4. Rizzi R, Re F, Bianchi A, et al. Mutagenic and antimutagenic
activities of Uncaria tomentosa and its extracts. J Ethnopharmacol
1993;38:63–77.
5. Rizzi R, Re F, Bianchi A, et al. Mutagenic and antimutagenic
activities of Uncaria tomentosa and its extracts. J Ethnopharmacol
1993;38:63–77.
6. 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.
7. Foster S. Herbs for Your Health. Loveland, CO: Interweave
Press, 1996, 18–9.