Cat’s Claw (Uncaria tomentosa): The Amazonian Vine in Wellness Formulas
Cat’s claw is a climbing vine from the Amazon basin, named for the curved thorns along its stems. It has a serious place in Peruvian traditional medicine and a growing research literature — plus a chemistry detail that most labels never mention but that genuinely matters.
- Botanical name
- Uncaria tomentosa
- Part used
- Inner bark and root bark
- Also found in
- ProstaDefend
What cat’s claw is
Uncaria tomentosa is a woody liana that climbs high into the canopy of the Amazon rainforest, found across Peru, Brazil, Ecuador, Colombia and neighbouring countries. Its Spanish name, uña de gato, comes from the pairs of curved thorns at the leaf nodes, which the plant uses to grip as it climbs.
The parts used are the inner bark of the vine and, in some preparations, the root bark. Harvesting is done by cutting sections of vine, which regrow, though pressure on wild populations has been an ongoing concern in Peru and has led to management regulations.
A closely related species, Uncaria guianensis, is also sold as cat’s claw and has a somewhat different chemistry. A third, entirely unrelated plant — the North American vine Macfadyena unguis-cati — shares the common name and is not the same thing.
Traditional use
Cat’s claw has a documented history in Asháninka and other Amazonian traditional practice, where decoctions of the bark are used for a range of complaints, notably inflammatory and digestive ones. The plant entered European awareness in the mid-twentieth century and has since become one of Peru’s better-known botanical exports.
Peru has regulated the harvest of Uncaria tomentosa to manage wild stocks, and cultivated material is increasingly available.
The two chemotypes — a detail worth knowing
This is the part that separates a well-made cat’s claw product from a careless one. Uncaria tomentosa occurs in two chemically distinct forms that look identical:
| Chemotype | Dominant alkaloids | Why it matters |
|---|---|---|
| Pentacyclic oxindole (POA) | Pteropodine, isopteropodine, mitraphylline and others | The type used in most research and in quality-controlled products. |
| Tetracyclic oxindole (TOA) | Rhynchophylline, isorhynchophylline | Acts on different targets; some research suggests TOAs may counteract POA activity. |
Because the two chemotypes cannot be told apart by eye, quality producers test raw material and specify a low TOA content. A label that says nothing about alkaloid profile is not necessarily bad, but it is telling you less.
What research has investigated
Most of the scientific work on cat’s claw is laboratory-based, examining its oxindole alkaloids and quinovic acid glycosides in relation to inflammatory signalling pathways and immune cell behaviour in culture.
Human trials exist but are limited in number and size. Several small studies looked at joint comfort over periods of a few months, using standardised extracts. Reviews of the area generally describe the human evidence as preliminary and call for larger trials.
Interest in cat’s claw for men’s formulas is largely about its studied role in inflammatory signalling as a general wellness contribution, rather than any prostate-specific research. That distinction is worth holding onto: being in a prostate formula is not the same as having been studied for the prostate.
The literature is indexed on PubMed.
Safety considerations
Cat’s claw has more interaction caveats than most botanicals on this list, and they are worth taking seriously.
- Immunosuppressant medication. Cat’s claw has been studied for effects on immune cell activity. Anyone taking immunosuppressants — after a transplant, or for an autoimmune condition — should avoid it unless a specialist says otherwise.
- Autoimmune conditions. For the same reason, caution is generally advised.
- Blood pressure medication. Possible additive effects; check with a pharmacist.
- Anticoagulants. Possible interaction; discuss before combining.
- Medicines processed by the liver. There is evidence cat’s claw may affect certain cytochrome P450 enzymes, which is the mechanism behind many drug interactions. If you take regular prescription medication, this is a pharmacist conversation.
- Pregnancy and breastfeeding. Not recommended.
- Before surgery. Stop at least two weeks beforehand.
Reported side effects are usually mild — headache, dizziness or digestive upset.
How it appears in supplements
Standalone products commonly supply 250–350 mg of bark extract daily, sometimes standardised to a stated oxindole alkaloid percentage. In multi-ingredient men’s formulas such as ProstaDefend, cat’s claw is one of six botanicals sharing the daily two-capsule serving, so the amount is smaller.
When comparing products, look for the species named in full (Uncaria tomentosa, not just “cat’s claw”), the plant part, and ideally something about alkaloid standardisation.
How to read this guide
This page describes a plant and what has been studied about it. It is not advice about whether you personally should take anything. Dietary supplements are not medicines. They are not intended to diagnose, treat, cure or prevent any disease. Information on this page is for general education and does not replace advice from a doctor, pharmacist or other qualified health professional.
Talk to your doctor before starting any supplement if you take prescription medication, have a diagnosed condition, or are scheduled for surgery.