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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.
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 approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
For More Information
The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
A service of the National Library of Medicine (NLM), PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals.
Office of Dietary Supplements (ODS), National Institutes of Health (NIH)
ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset.
- 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.
This publication is not copyrighted and is in the public domain. Duplication is encouraged.