Cat’s Claw

Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD — GMJ Editorial Board

What is Cat’s Claw?

Cat’s claw (Uncaria tomentosa) is a woody vine native to the Amazon rainforest and other tropical areas of South and Central America. Also known as “uña de gato” in Spanish, this climbing vine gets its name from the curved, claw-like thorns that grow along its stem. For centuries, indigenous Peruvian tribes have used cat’s claw bark and root as traditional medicine.

The plant contains several bioactive compounds, including oxindole alkaloids, quinovic acid glycosides, and various polyphenols. Cat’s claw is primarily classified as an immune-supporting botanical supplement rather than an omega or fatty acid supplement. Two main species are used medicinally: Uncaria tomentosa and Uncaria guianensis, with U. tomentosa being more commonly studied and used in supplements.

Health benefits & uses

Immune system support (Moderate evidence): Several studies suggest cat’s claw may help modulate immune function. Research indicates it may enhance white blood cell activity and support the body’s natural defense mechanisms, though more human trials are needed to confirm these effects.

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Anti-inflammatory effects (Moderate evidence): Cat’s claw contains compounds that may help reduce inflammation markers. Some studies have shown promising results for reducing joint pain and inflammation, particularly in osteoarthritis patients, though the evidence remains limited.

Antioxidant activity (Limited evidence): Laboratory studies demonstrate that cat’s claw extracts possess antioxidant properties, potentially helping to neutralize harmful free radicals. However, human studies confirming these benefits are lacking.

Digestive health (Limited evidence): Traditional use and some preliminary research suggest cat’s claw might support digestive health, but clinical evidence is insufficient to make definitive claims.

How it works

Cat’s claw’s potential health effects are attributed to its diverse array of bioactive compounds. The oxindole alkaloids, particularly pentacyclic oxindole alkaloids (POAs), appear to be key components responsible for immune-modulating effects. These compounds may help regulate immune cell function and cytokine production.

The plant’s anti-inflammatory properties likely stem from its ability to inhibit nuclear factor-kappa B (NF-κB), a protein complex that regulates inflammatory responses. Quinovic acid glycosides and other compounds may contribute to antioxidant activity by scavenging free radicals and supporting cellular protection mechanisms.

Dosage

Cat’s claw supplements are typically available as capsules, tablets, tinctures, or powders. There is no established Recommended Dietary Allowance (RDA) or Upper Limit (UL) for cat’s claw, as it is not considered an essential nutrient.

Common dosage ranges for adults include:

• Standardized extract (containing 3% alkaloids): 20-60 mg daily
• Dried bark powder: 500-1000 mg, 1-3 times daily
• Liquid extract: 1-4 mL daily

Always consult with a healthcare provider before starting cat’s claw supplementation, especially if you have underlying health conditions or take medications. Start with lower doses to assess tolerance.

Food sources

Cat’s claw is not found in conventional foods and is not part of a typical diet. The medicinal compounds are concentrated in the bark and root of the vine, which require specific preparation methods to extract beneficial compounds. Cat’s claw is exclusively available as a dietary supplement in forms such as:

• Capsules or tablets containing dried bark extract
• Liquid tinctures or extracts
• Powdered bark preparations
• Tea preparations (though these may be less potent than concentrated extracts)

Safety & side effects

Cat’s claw is generally well-tolerated by most adults when used short-term. However, some individuals may experience side effects including:

• Digestive upset, nausea, or diarrhea
• Dizziness or headaches
• Low blood pressure (hypotension)
• Allergic reactions in sensitive individuals

Long-term safety data is limited, so prolonged use should be monitored by a healthcare provider. The quality and purity of cat’s claw supplements can vary significantly between manufacturers, making it important to choose products from reputable sources.

Interactions

Cat’s claw may interact with several medications and supplements:

Blood pressure medications: Cat’s claw may enhance blood pressure-lowering effects, potentially causing hypotension.

Immunosuppressive drugs: Since cat’s claw may stimulate immune function, it could potentially interfere with medications designed to suppress the immune system, such as those used after organ transplants.

Blood-thinning medications: Some evidence suggests cat’s claw might affect blood clotting, though research is limited.

CYP3A4 substrates: Cat’s claw may influence liver enzyme activity, potentially affecting the metabolism of certain medications.

Who should be cautious

Certain groups should exercise particular caution or avoid cat’s claw supplementation:

• Pregnant and breastfeeding women: Safety data is insufficient
• Autoimmune disease patients: Cat’s claw’s immune-stimulating effects may worsen conditions like multiple sclerosis, lupus, or rheumatoid arthritis
• Organ transplant recipients: May interfere with immunosuppressive therapy
• Individuals with low blood pressure: May further reduce blood pressure
• People scheduled for surgery: Should discontinue use at least two weeks before surgery due to potential bleeding risks

Frequently asked questions

Is cat’s claw the same as cat’s claw acacia?

No, cat’s claw (Uncaria tomentosa) is different from cat’s claw acacia (Acacia greggii). They are entirely different plants with different properties. Make sure you’re purchasing the correct Uncaria tomentosa supplement.

How long does it take to see benefits from cat’s claw?

Individual responses vary, but some people report noticing effects within a few weeks of consistent use. However, immune-supporting supplements often require longer periods of use to show meaningful benefits, and results may be subtle.

Can I take cat’s claw with other immune supplements?

While cat’s claw can generally be combined with other supplements, it’s important to consult a healthcare provider, especially when combining multiple immune-supporting products. This helps avoid excessive immune stimulation and potential interactions.

Should I cycle cat’s claw supplementation?

Some practitioners recommend taking breaks from cat’s claw supplementation, such as using it for 2-3 months followed by a 1-month break. However, there’s no established protocol, so discuss the best approach with your healthcare provider.

Is cat’s claw sustainable and ethically sourced?

Look for suppliers who practice sustainable harvesting methods and support indigenous communities. Some certification programs ensure ethical sourcing of rainforest botanicals like cat’s claw.