Cat's Claw (Uncaria tomentosa)
Commonly used for
Joint HealthImmune Support
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What is it? / Overview
Wellness uses some people report: general immune and antiviral support. This is anecdotal, and there isn't strong clinical evidence that it works for everyone. Cat's claw constituents potently inhibit TNF-alpha production and NF-kB signaling and scavenge free radicals, producing anti-inflammatory effects. A randomized trial found freeze-dried extract reduced knee osteoarthritis pain within a week and was well tolerated -- the strongest human evidence in this batch is for joint symptom relief, not the general immune-support framing it's often marketed under.
How is it used? / Administration
Form: Uncaria tomentosa (and U. guianensis) bark/root extract, aqueous or hydroethanolic -- alkaloid content varies by preparation
Typical dose studied: Varies by preparation -- the osteoarthritis trial used a freeze-dried extract around 100 mg/day
Timing: Daily with food
CYP3A4 inhibition gives this a broader drug-interaction footprint than most botanicals in this database -- worth a pharmacist check for anyone on multiple medications.
How well does it work? / Evidence
? Emerging / limited evidence
Who should avoid it?
Avoid with: Organ transplant (on immunosuppression); Bleeding disorder / Coagulopathy; Breastfeeding
Interacts with: Immunosuppressants -- theoretical antagonism; Anticoagulants, antiplatelets -- theoretical additive bleeding risk; CYP3A4-metabolized drugs (many statins, calcineurin inhibitors) -- cat's claw inhibits CYP3A4, a broad interaction-risk flag
Already taking it? Best human evidence is for knee osteoarthritis symptom relief specifically, not general immune support -- reasonable to continue for joint discomfort, but the CYP3A4 interaction potential is broad enough to be worth mentioning to a doctor or pharmacist if taking other medications.
Research & references
Piscoya J et al. (2001). Efficacy and Safety of Freeze-Dried Cat's Claw in Osteoarthritis of the Knee. Inflammation Research. Arado GM et al. (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.
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