Wise Mind Herbs

The information on this page has been prepared with reference to published scientific literature, not by a medically qualified expert. It is not medical advice. Any decision to use a supplement or herb-based product is your responsibility. Consult a suitably qualified medical professional, especially if you have underlying conditions. Remember, nothing is for everyone, and not everything sold is what it claims to be. Some things work for some people, some of the time.

Cat's Claw (Uncaria tomentosa)

Cat's claw (Uncaria tomentosa) is a woody vine native to the Amazon rainforest and other tropical areas of South and Central America. Its name derives from the hook-like thorns that resemble a cat's claw. The plant has been used in traditional medicine by indigenous peoples, particularly in Peru, for centuries.

Image source and license: https://commons.wikimedia.org/wiki/File:Uncaria_tomentosa.png.
Modified by Peter Jorgensen.

Common Names and Botanical Classification

Uncaria tomentosa is commonly known as cat's claw, uña de gato, hawk's claw, and life-giving vine of Peru. It should not be confused with Uncaria guianensis (which is also sometimes called cat's claw or uña de gato but has different properties), Acacia greggii (cat's claw acacia), or Macfadyena unguis-cati (cat's claw vine or cat's claw creeper). These plants, despite sharing similar common names, have distinct chemical compositions and potential health effects.

Bioactive Compounds

The primary bioactive compounds in Uncaria tomentosa include alkaloids (particularly oxindole alkaloids such as pentacyclic oxindole alkaloids or POAs), quinovic acid glycosides, polyphenols, procyanidins, and triterpenes. The pentacyclic oxindole alkaloids are often considered the primary active constituents responsible for the immunomodulatory effects, while other compounds contribute to its anti-inflammatory and antioxidant properties.

Potential Health Benefits Based on Scientific Evidence

Research on cat's claw has revealed several potential health benefits, although it's important to note that many studies are preliminary, conducted in vitro or in animal models, with fewer well-designed human clinical trials available.

• Anti-inflammatory effects: Multiple studies have demonstrated the anti-inflammatory properties of cat's claw extracts, potentially beneficial for inflammatory conditions like arthritis.
• Immune system modulation: Research suggests cat's claw may enhance immune function through various mechanisms including stimulation of phagocytosis and increasing lymphocyte proliferation.
• Antioxidant activity: The plant contains compounds that exhibit significant antioxidant effects, potentially protecting cells from oxidative damage.
• Arthritis symptom reduction: Several small clinical trials have shown improvement in pain and stiffness in both osteoarthritis and rheumatoid arthritis patients.
• Digestive disorders: Some evidence suggests benefits for certain gastrointestinal conditions, including inflammation of the digestive tract.
• Viral infections: In vitro studies indicate potential antiviral activity against various viruses, though clinical evidence is limited.
• DNA repair enhancement: Laboratory research suggests cat's claw may help repair DNA damage from environmental factors.
• Potential anticancer properties: Preliminary research has shown cytotoxic effects against certain cancer cell lines, though this research is still in early stages.

Conditions with Some Scientific Support

While cat's claw is sometimes promoted as a "cure" for various conditions, current scientific evidence does not support claims of it curing any disease. There is, however, evidence suggesting it may help alleviate symptoms or provide benefits for:

• Osteoarthritis and rheumatoid arthritis (reduced pain and inflammation)
• Inflammatory bowel conditions (reduced inflammation)
• Immune system support during chemotherapy and radiation treatments
• Certain viral infections (as adjunctive therapy)

Recommended Dosages

Dosages used in clinical studies have varied widely, making standardized recommendations difficult. Most commercial preparations are standardized to their alkaloid or procyanidin content.

• For dried root capsules: 250-1000 mg taken 1-3 times daily
• For standardized extract (standardized to contain 3% alkaloids or 15% procyanidins): 250-300 mg taken 1-3 times daily
• For tea preparation: 1000 mg dried bark steeped in 8 oz of water for 10-15 minutes, consumed up to three times daily
• For liquid extract (4:1): 1-4 mL taken 1-3 times daily

Most clinical studies showing efficacy for arthritis have used cat's claw extracts standardized to contain either 3% pentacyclic oxindole alkaloids or 15% procyanidins at doses of 100 mg three times daily.

Side Effects and Safety Concerns

Cat's claw is generally considered safe for most adults when taken at recommended dosages for short periods (up to 12 weeks in clinical trials). However, several side effects and safety concerns have been documented:

• Gastrointestinal effects: Nausea, diarrhea, and abdominal discomfort are the most commonly reported side effects
• Headache and dizziness
• Allergic reactions in some individuals
• Potential blood pressure lowering effects
• Risk of bleeding: May slow blood clotting
• Possible interference with immune system medications and immunosuppressants

Contraindications

Cat's claw should be avoided by:

• Pregnant and breastfeeding women (may stimulate uterine contractions)
• People with autoimmune disorders (due to immune-stimulating effects)
• Individuals with bleeding disorders or taking anticoagulant medications
• Patients scheduled for surgery (discontinue at least 2 weeks before)
• Organ transplant recipients and others taking immunosuppressive drugs
• People with low blood pressure or taking blood pressure medications

Disbenefits and Concerns

Several concerns have been raised regarding cat's claw supplementation:

• Variable product quality and standardization in commercial supplements
• Insufficient regulation and quality control in many markets
• Potential misidentification with other Uncaria species or adulterants
• Potential for drug interactions with conventional medications
• Limited long-term safety data
• Overharvesting concerns for wild populations

High-Dose Studies and Knowledge Gaps

Research on high doses of cat's claw (above the commonly recommended therapeutic range) is limited. Animal toxicity studies have used significantly higher doses than those recommended for humans without observing serious adverse effects, suggesting a relatively wide safety margin. However, formal dose-escalation studies in humans are lacking, representing a significant knowledge gap. No established maximum effective dose has been determined through systematic research, and the relationship between dose and efficacy for specific conditions remains poorly characterized.

There is insufficient evidence to suggest benefits from doses higher than those typically recommended, and higher doses may increase the risk of side effects and drug interactions. Long-term safety studies are notably absent from the literature, creating uncertainty about the effects of extended use.

Commercial Pharmaceutical Products

Unlike some herbal medicines, cat's claw has not been widely developed into standardized pharmaceutical drugs approved by major regulatory agencies like the FDA or EMA.

References

Arado, G. M., Amatto, P. D. P. G., Marins, M., Rizzi, E. S., França, S. D. C., Coppede, J. D. S., ... & Pereira, A. M. S. (2024). Anti-inflammatory and/or immunomodulatory activities of Uncaria tomentosa (cat’s claw) extracts: A systematic review and meta-analysis of in vivo studies. Frontiers in Pharmacology, 15, 1378408.

Batiha, G. E. S., Magdy Beshbishy, A., Wasef, L., Elewa, Y. H., Abd El-Hack, M. E., Taha, A. E., ... & Tufarelli, V. (2020). Uncaria tomentosa (Willd. ex Schult.) DC.: A review on chemical constituents and biological activities. Applied Sciences, 10(8), 2668.

Bors, M., Michałowicz, J., Pilarski, R., Sicińska, P., Gulewicz, K., & Bukowska, B. (2012). Studies of biological properties of Uncaria tomentosa extracts on human blood mononuclear cells. Journal of ethnopharmacology, 142(3), 669-678.

Ciani, F., Tafuri, S., Troiano, A., Cimmino, A., Fioretto, B. S., Guarino, A. M., ... & Calabrò, V. (2018). Anti-proliferative and pro-apoptotic effects of Uncaria tomentosa aqueous extract in squamous carcinoma cells. Journal of ethnopharmacology, 211, 285-294.

Kolodziejczyk-Czepas, J., Ponczek, M., Sady-Janczak, M., Pilarski, R., & Bukowska, B. (2021). Extracts from Uncaria tomentosa as antiplatelet agents and thrombin inhibitors–the in vitro and in silico study. Journal of Ethnopharmacology, 267, 113494.

Lin, C. H., Chiu, H. E., Wu, S. Y., Tseng, S. T., Wu, T. C., Hung, Y. C., ... & Hu, W. L. (2021). Chinese herbal products for non-motor symptoms of Parkinson’s disease in Taiwan: a population-based study. Frontiers in Pharmacology, 11, 615657.

Reis, S. R. I., Valente, L. M., Sampaio, A. L., Siani, A. C., Gandini, M., Azeredo, E. L., ... & Kubelka, C. F. (2008). Immunomodulating and antiviral activities of Uncaria tomentosa on human monocytes infected with Dengue Virus-2. International immunopharmacology, 8(3), 468-476.

Zari, A., Alfarteesh, H., Buckner, C., & Lafrenie, R. (2021). Treatment with Uncaria tomentosa promotes apoptosis in B16-BL6 mouse melanoma cells and inhibits the growth of B16-BL6 tumours. Molecules, 26(4), 1066.