Cat’s Claw

© Steven Foster

This fact sheet provides basic information about cat’s claw—common 

names, what the science says, potential side effects and cautions, and 

resources for more information. 

Common Names—cat’s claw, uña de gato

Latin Names—Uncaria tomentosa, Uncaria guianensis

Cat’s claw grows wild in many countries of Central and South America, 

especially in the Amazon rainforest. The use of this woody vine dates 

back to the Inca civilization. Historically, cat’s claw has been used for 

centuries in South America to prevent and treat disease. More recently, 

cat’s claw has been used as a folk or traditional remedy for a variety of 

health conditions, including viral infections (such as herpes and HIV), 

Alzheimer’s disease, cancer, and arthritis. Other folk uses include 

supporting the immune system and promoting kidney health, as well 

as preventing and aborting pregnancy.

The inner bark of cat’s claw is used to make liquid extracts, capsules, 

and teas. Preparations of cat’s claw can also be applied to the skin.

What the Science Says 

• There is not enough scientific evidence to determine whether cat’s 

claw works for any health condition.

• Small studies in humans have shown a possible benefit of cat’s claw 

in osteoarthritis and rheumatoid arthritis, but no large trials have 

been done. In laboratory studies, cat’s claw stimulates part of the 

immune system, but it has not been proven to reduce inflammation 

or boost the immune system in humans.

• The National Institute on Aging funded a study that looked at how 

cat’s claw may affect the brain. Findings may point to new avenues 

for research in Alzheimer’s disease treatment.
Side Effects and Cautions

• Few side effects have been reported for cat’s claw when it is taken at recommended 

dosages. Though rare, side effects may include headaches, dizziness, and vomiting.

• Women who are pregnant or trying to become pregnant should avoid using cat’s claw

because of its past use for preventing and aborting pregnancy.

• Because cat’s claw may stimulate the immune system, it is unclear whether the herb is 

safe for people with conditions affecting the immune system.

• Cat’s claw may interfere with controlling blood pressure during or after surgery.

• Tell all your health care providers about any complementary health practices you use. Give 

them a full picture of what you do to manage your health. This will help ensure 

coordinated and safe care. For tips about talking with your health care providers about 

complementary and alternative medicine, see NCCAM’s Time to Talk campaign at 

nccam.nih.gov/timetotalk/. 

Sources

Cat’s claw. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on May 6, 2009.

Cat’s claw (Uncaria tomentosa, Uncaria guianensis). Natural Standard Database Web site. Accessed at 

www.naturalstandard.com on May 6, 2009.

For More Information

Visit the NCCAM Web site at nccam.nih.gov and view Using Dietary Supplements Wisely

(nccam.nih.gov/health/supplements/wiseuse.htm).

NCCAM Clearinghouse

Toll-free in the U.S.: 1-888-644-6226

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615

E-mail: info@nccam.nih.gov

PubMed®

Web site: www.ncbi.nlm.nih.gov/sites/entrez

NIH Office of Dietary Supplements

Web site: www.ods.od.nih.gov

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the 

medical expertise and advice of your primary health care provider. We encourage you to 

discuss any decisions about treatment or care with your health care provider. The mention of 

any product, service, or therapy is not an endorsement by NCCAM.

National Institutes of Health

♦♦♦

U.S. Department of Health and Human Services

D334

Created December 2006

Updated April 2012