Cat's claw
Cat's claw is the name for Uncaria tomentosa and Uncaria guianensis, woody vines from tropical parts of Central and South America.
Also listed as Vincaria, Uncaria Tomentosa, Uncaria guianensis, Cat's Claw Extract
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What is cat’s claw?
Cat’s claw refers to Uncaria tomentosa and Uncaria guianensis, woody vines from tropical parts of the Americas. Human research remains limited, despite its use in supplements. 1
Why are researchers interested in it?
Cell experiments suggest that compounds called oxindole alkaloids affect immune-cell activity and inflammatory signaling. These mechanisms offer reasons to study the plant; they do not establish that it prevents infections or treats digestive disease in people. 2
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Can it replace rheumatoid arthritis medicine?
The positive trial added an extract to existing medicine; it did not test replacement. 3
Does the knee trial show relief at night?
No significant improvement in night pain was found in that four-week trial. 4
Does “immune support” mean fewer infections?
Immune-cell effects in laboratory experiments do not establish infection prevention in people. 2
Why did a poison center warn about cat’s claw?
The 2026 US alert concerned products with undeclared drug ingredients sold under the herb’s name. 5
Devil's Claw