NutriStack
SeriousCaution
HIV Protease Inhibitors
Cat's claw inhibits CYP3A4 more potently than ketoconazole in vitro. Documented interactions with atazanavir, ritonavir, saquinavir.
Recommendation: Avoid concurrent use.
Cat's Claw
Herb ·Emerging evidence ·Reviewed May 2026
Amazonian vine used for immune support and joint inflammation.
The bottom line
Evidence rating emerging. Most-documented uses: immune support, joint health, anti-inflammatory. 18 sources indexed (1998–2024), with 4 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Pentacyclic oxindole alkaloids stimulate immune cell proliferation. Quinovic acid glycosides provide anti-inflammatory action. Inhibits TNF-alpha and NF-κB.8,9
Class
Anti-Inflammatory Vine
Absorption
Water-soluble; take with food
Dosing
Dosing & protocol.
Common range
250-1,000 mg daily
Recommended form
Inner bark extract (pentacyclic alkaloid chemotype preferred)
Take with food
Dosing protocol
Maintain · 250-350 mg/day standardized extract
TOA-free preparations may be better tolerated. Avoid in autoimmune flare without supervision.
No cycling requiredNo tolerance buildup
Forms
Forms & what to buy.
Ranked by evidence and value.
TOA-Free Cat's Claw Extract Recommended
Rank 1: standardized extract intended to emphasize POA alkaloids. Limited direct form-comparison evidence; ranking is based on review or mechanistic data (PMID: 39430457). Human form-comparison evidence is limited.
Standard Bark Extract
Rank 2: common concentrated bark extract. Take with meals if GI upset occurs.
Bark Powder or Tea
Rank 3: traditional whole bark form. Requires larger amounts than extracts.
Cost
What it actually costs.
Real-world pricing across three quality tiers. Assumes Inner Bark Extract.
BudgetBest value
$3.60 /mo
$0.12 per dose
Mid
$8.40 /mo
$0.28 per dose
Premium
$16.50 /mo
$0.55 per dose
Assumes 250-1,000 mg/day. Vendor basis: NOW/iHerb, Vitacost, Amazon marketplace, and specialty herb brands; POA-focused extracts cost more. Updated 2026-05-28.
From food
The same dose, as food.
How much you'd eat to match a supplemental dose.
250-1,000 mg cat's claw extract
Not applicable as a whole-food equivalent.
Cat's claw is a medicinal vine bark extract and is not an ordinary dietary food.
Lab work
Markers to track.
What to test, the optimal window inside the conventional range, and how long a response takes.
hsCRP
Uncaria tomentosa (250 to 350 mg per day) modestly lowers inflammatory markers in rheumatoid arthritis and osteoarthritis RCTs; clinical effect size is moderate.1,2
Optimal
0–1 mg/L
Conventional
0–3 mg/L
Responds in
Joint symptoms within 4 to 8 weeks; hsCRP over 8 to 12 weeks.
0optimal3
TOA-free (tetracyclic oxindole alkaloid free) preparations may be better tolerated. Pair with WOMAC or DAS28 scores.
ESR
Safety
Full safety detail.
Interactions
Interaction records.
InfoSynergy
Turmeric/Curcumin
Combined use broadens anti-inflammatory coverage by suppressing NF-kB driven cytokine production through complementary pathways, supporting joint comfort.
Recommendation: Reasonable to stack for joint or inflammatory support. Take with food and monitor for any added GI upset.
ModerateCaution
Fish Oil
Both agents have mild antiplatelet activity, so combining them may modestly increase bleeding tendency, especially with anticoagulant or antiplatelet drugs.
Recommendation: Generally fine for most people, but monitor for easy bruising or bleeding and stop both 1 to 2 weeks before surgery. Use caution if on blood thinners.
InfoSynergy
Boswellia
Pairing provides complementary anti-inflammatory action, with Boswellia inhibiting 5-lipoxygenase and Cat's Claw suppressing NF-kB signaling.
Recommendation: Reasonable to combine for joint and inflammatory support. No timing constraint needed; take with food to improve tolerability.
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
1- 1Anti-inflammatory and/or immunomodulatory activities of Uncaria tomentosa (cat's claw) extracts: A systematic review and meta-analysis of in vivo studiesNeeds reviewPMIDBatiha GE et al. · Journal of Ethnopharmacology · 2024
Extracts decreased NF-kB and IL-6 with low toxicity; findings suggest potential to treat inflammatory diseases where these markers are elevated.
Randomized controlled trials
3- 2Evaluation of different treatment methods against denture stomatitis: a randomized clinical studyNeeds reviewPMIDTay LY, Jorge JH, Herrera DR, Campanha NH, Gomes BP, Andre Dos Santos F · Oral Surg Oral Med Oral Pathol Oral Radiol · 2014
RCT of 50 patients with denture stomatitis found 2% Uncaria tomentosa gel was equally effective as 2% miconazole gel in treating denture stomatitis, reducing both severity and Candida colony counts.
- 3Efficacy and safety of freeze-dried cat's claw in osteoarthritis of the knee: mechanisms of action of the species Uncaria guianensisNeeds reviewPMIDPiscoya J et al. · Inflammation Research · 2001
In 45 patients, freeze-dried cat's claw significantly reduced pain with activity; benefits occurred within the first week of therapy.
- 4Efficacy and safety of freeze-dried cat's claw in osteoarthritis of the kneeSource linkedPMIDPiscoya J, Rodriguez Z, Bustamante SA et al. · Inflamm Res · 2001
Reviews & position papers
9- 5Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosaNeeds reviewPMIDDuchnowicz P, Pilarski R, Michałowicz J et al. · Molecules (Basel, Switzerland) · 2021
Duchnowicz P, Pilarski R, Michałowicz J et al.. Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosa. Molecules (Basel, Switzerland). 2021
- 6A spray containing extracts of oat plantlets and Uncaria tomentosa relieves pain associated with chronic inflammatory skin diseases and dermatological proceduresNeeds reviewPMIDReich A, Lopez Estebaranz JL, Bahadoran P et al. · Journal of the European Academy of Dermatology and Venereology : JEADV · 2020
Reich A, Lopez Estebaranz JL, Bahadoran P et al.. A spray containing extracts of oat plantlets and Uncaria tomentosa relieves pain associated with chronic inflammatory skin diseases and dermatological procedures. Journal of the European Academy of Dermatology and Venereology : JEADV. 2020
- 7Investigating Potential Inhibitory Effect of Uncaria tomentosa (Cat's Claw) against the Main Protease 3CL(pro) of SARS-CoV-2 by Molecular ModelingNeeds reviewPMIDYepes-Pérez AF, Herrera-Calderon O, Sánchez-Aparicio JE et al. · Evidence-based complementary and alternative medicine : eCAM · 2020
Yepes-Pérez AF, Herrera-Calderon O, Sánchez-Aparicio JE et al.. Investigating Potential Inhibitory Effect of Uncaria tomentosa (Cat's Claw) against the Main Protease 3CL(pro) of SARS-CoV-2 by Molecular Modeling. Evidence-based complementary and alternative medicine : eCAM. 2020
- 8Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell lineNeeds reviewPMIDDietrich F, Kaiser S, Rockenbach L et al. · Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association · 2014
Dietrich F, Kaiser S, Rockenbach L et al.. Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 2014
- 9Effect of Uncaria tomentosa Extract on Apoptosis Triggered by Oxaliplatin Exposure on HT29 CellsNeeds reviewPMIDde Oliveira LZ, Farias IL, Rigo ML et al. · Evidence-based complementary and alternative medicine : eCAM · 2014
de Oliveira LZ, Farias IL, Rigo ML et al.. Effect of Uncaria tomentosa Extract on Apoptosis Triggered by Oxaliplatin Exposure on HT29 Cells. Evidence-based complementary and alternative medicine : eCAM. 2014
- 10Reversible worsening of Parkinson disease motor symptoms after oral intake of Uncaria tomentosa (cat's claw)Needs reviewPMIDCosentino C, Torres L · Clinical neuropharmacology · 2008
Cosentino C, Torres L. Reversible worsening of Parkinson disease motor symptoms after oral intake of Uncaria tomentosa (cat's claw). Clinical neuropharmacology. 2008
- 11Cat's claw: an Amazonian vine decreases inflammation in osteoarthritisNeeds reviewPMIDHardin SR · Complementary Therapies in Clinical Practice · 2007
Pain associated with activity, medical and patient assessment scores were all significantly reduced with cat's claw treatment.
- 12Cat's Claw (Uncaria tomentosa) for osteoarthritis: a systematic reviewNeeds sourceNo linkMehta K, Gala J, Bhasale S et al. · J Altern Complement Med · 2007
- 13Cat's claw (Uncaria tomentosa) and its anti-inflammatory activity: a reviewSource linkedPMIDSandoval M, Charbonnet RM, Okuhama NN et al. · J Ethnopharmacol · 2000
Mechanistic & preclinical
3- 14Uncaria tomentosa acts as a potent TNF-alpha inhibitor through NF-kappaBNeeds reviewPMIDAllen-Hall L et al. · Journal of Ethnopharmacology · 2010
U. tomentosa inhibits TNF-alpha production through NF-kB-dependent mechanism; LPS-dependent TNF-alpha expression inhibited 5.5-fold.
- 15Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotectionNeeds reviewPMIDSandoval M et al. · Free Radical Biology and Medicine · 2000
Cat's claw species are effective antioxidants; anti-inflammatory properties result from ability to inhibit TNF-alpha and PGE2 production.
- 16Antiinflammatory actions of cat's claw: the role of NF-kappaBNeeds reviewPMIDSandoval-Chacon M et al. · Alimentary Pharmacology & Therapeutics · 1998
Cat's claw inhibits NF-kappaB activation, which is a key mechanism underlying its anti-inflammatory effects.
Reference material
2- 17Marques O, Figueirinha A, Pina ME et al.. Uncaria tomentosa as a Promising Natural Source of Molecules with Multiple Activities: Review of Its Ethnomedicinal Uses, Phytochemistry and Pharmacology. International journal of molecular sciences. 2025Source linkedPMID
- 18Yepes-Pérez AF, Herrera-Calderon O, Quintero-Saumeth J. Uncaria tomentosa (cat's claw): a promising herbal medicine against SARS-CoV-2/ACE-2 junction and SARS-CoV-2 spike protein based on molecular modeling. Journal of biomolecular structure & dynamics. 2022Source linkedPMID
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Cat's Claw in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.