The Uses and Benefits of Cat's Claw

cat's claw (uncaria tomentosa)
Manfred Pfefferie/Oxford Scientific/Getty Images

Cat's claw is a vine with hook-like thorns that resemble the claws of a cat. Native to the Amazon and Central American rainforests, cat’s claw bark and root have been used for centuries by South Americans as a remedy for inflammatory conditions like arthritis and gastritis.

It is also known as Uncaria tomentosa, Uncaria guianesis, una de gato, and life-giving vine of Peru.

The Benefits of Cat's Claw: Can It Really Help?

Early research suggests that cat’s claw may have immune-modulating and antioxidant properties, lower blood pressure, and act as a diuretic.

1) Rheumatoid Arthritis

The cat's claw compound pentacyclic oxindolic alkaloid is thought to have anti-inflammatory effects, blocking the body's production of inflammation-producing substances such as tumor necrosis factor alpha (TNF-alpha).

A small, older study published in The Journal of Rheumatology in 2002 found that people with rheumatoid arthritis who took a standardized extract of cat's claw for one year (in addition to their medication) had a reduction in the number of painful joints compared to a placebo. During the study, only minor side effects were observed.

2) Osteoarthritis

For a small study published in Inflammation Research, people with osteoarthritis of the knee took either a cat's claw extract or a placebo. After four weeks, a significantly greater number of those who took the cat's claw extract had reduced pain during activity. Pain at rest or at night and knee swelling weren't reduced. During the treatment period, there were no significant side effects or changes in blood or liver function.

3) Lyme Disease

A substance extracted from cat's claw called samento is sometimes recommended to fight bacteria and inflammation in people with Lyme disease. Unlike cat's claw, samento is free of tetracyclic oxindole alkaloids (TOAs), compounds that can weaken the effects of the active compound (pentacyclic oxindole alkaloids, or POAs).

4) Cancer

Some early test tube studies suggest pentacyclic oxindole alkaloids (POA) found in cat's claw may have antitumor activity, however, we need much more evidence before we can draw conclusions about its effectiveness or use it as a cancer treatment (and it should never be used to replace conventional care).

5) Other Conditions

Cat's claw has also been used for anxiety, acne, allergies, high blood pressure, candida, fibroids, gout, gastritis, ovarian cysts, sexually transmitted diseases (STDs), tendonitis, tinnitus, and ulcerative colitis, but there's insufficient evidence on the effectiveness of cat's claw for these conditions.

Possible Side Effects

Cat’s claw has been used as a remedy for centuries, which may lead you to believe that it’s safe, however, there hasn’t been enough research to determine its safety.

Side effects that have been reported include nausea, headache, dizziness, diarrhea, and low blood pressure. One report linked cat’s claw to acute interstitial nephritis (an allergic, inflammatory reaction in the kidneys), and a case study reported that a woman taking silica-containing supplements (including cat’s claw) developed kidney stones made entirely of silicate.

If you take medication, you should ask your doctor before taking cat’s claw. The herb can alter the effectiveness of many drugs, such as:

  • Allergy medication such as fexofenadine
  • Antifungals such as ketoconazole
  • Antiretrovirals
  • Blood pressure medication
  • Blood-thinning medications
  • Cancer medications such as paclitaxel or vinblastine
  • Cholesterol medication such as lovastatin
  • Diuretics
  • Immune suppressants 
  • Oral contraceptives

If you have autoimmune disease (e.g. type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, and Crohn's disease), bleeding disorders, tuberculosis, leukemia, liver disease, kidney disease, or have had an organ transplant, you shouldn’t take cat’s claw except under your doctor’s supervision. It should be discontinued at least two weeks before scheduled surgery.

Pregnant and breastfeeding women and children shouldn’t take cat’s claw.

Cat's claw shouldn't be confused with another herb called cat's claw acacia (or catclaw acacia, una de gato, or Acacia gregii), which is believed to contain a compound related to cyanide and shouldn't be taken orally.

A Word From Verywell

Despite its popularity, the research on cat's claw is limited to a couple of older, small trials and test tube studies. Until there are large-scale trials confirming the effects, it's too soon to recommend cat's claw as a treatment for any condition.

While the studies that have been done didn't find significant side effects, cat's claw has the potential to interact with a number of medications and should be avoided if you have certain health conditions. If you're still thinking of trying it, be sure to consult your primary care provider before taking it to discuss whether it's appropriate for you.

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Article Sources
  • Kaiser S, Carvalho ÂR, Pittol V, et al. Genotoxicity and Cytotoxicity of Oxindole Alkaloids From Uncaria Tomentosa (Cat's Claw): Chemotype Relevance. J Ethnopharmacol. 2016 Aug 2;189:90-8.

  • Montserrat-de la Paz S, Fernandez-Arche A, de la Puerta R, Quilez AM, Muriana FJ, Garcia-Gimenez MD, Bermudez B. Mitraphylline Inhibits Lipopolysaccharide-Mediated Activation of Primary Human Neutrophils. Phytomedicine. 2016 Feb 15;23(2):141-8.

  • Mur E, Hartig F, Eibl G, Schirmer M. Randomized Double Blind Trial of an Extract From the Pentacyclic Alkaloid-Chemotype of Uncaria Tomentosa for the Treatment of Rheumatoid Arthritis. J Rheumatol. 2002 Apr;29(4):678-81.

  • 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 Res. 2001 Sep;50(9):442-8.