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Dietary supplement

Cat's Claw Bark Ingredients & Drug Interactions

by Cedar Bear

Cat's Claw Bark label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Cat's Claw Bark against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Cat's Claw Bark is a dietary supplement by Cedar Bear with 1 active ingredient. Its ingredients are commonly taken for osteoarthritis and rheumatoid arthritis, inflammation, immune support.Based on those ingredients, 962 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Cat's Claw. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Cat's Claw Bark by Cedar Bear

Ask about any prescription or over-the-counter medication and we check it for interactions with Cat's Claw Bark by Cedar Bear — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Cat's Claw Bark by Cedar Bear

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 12, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 1 active ingredient.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (0.50 mL) without saying how much of each component you get.

This product contains one active ingredient: cat's claw, an extract from the bark of a tropical vine. The liquid is made with vegetable glycerin and purified water as inactive ingredients.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Cat's Claw's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: joint and immune support.
  • We looked for evidence on: Osteoarthritis, Rheumatoid arthritis (RA), Inflammatory bowel disease (IBD), inflammation, immune function, digestive health.
  • The closest evidence on file: Cat's Claw is rated "Insufficient Reliable Evidence To Rate" for Inflammatory bowel disease (IBD) (Natural Medicines).
  • Also on file: Cat's Claw is rated "Insufficient Reliable Evidence To Rate" for Osteoarthritis, Rheumatoid arthritis (RA).

The evidence we hold doesn't establish that cat's claw is effective for any of the conditions it's marketed for — hay fever, Alzheimer disease, asthma, osteoporosis, cancer, or chronic fatigue syndrome all carry a rating of insufficient reliable evidence. That doesn't mean it doesn't work; it means the clinical data isn't solid enough yet for us to say one way or the other.

The evidence, ingredient by ingredient Cat's Claw

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Cat's claw is generally well tolerated in the short term for healthy adults, but we don't have good long-term safety data. In one clinical trial of patients with advanced cancer, a small number experienced low red blood cell counts (12%), and even fewer had low white blood cells or low platelets (2% each).

Several case reports have linked cat's claw to kidney injury, so if you have kidney disease or lupus, be extra cautious. Headache, fatigue, insomnia, and nerve damage showed up in a small percentage of trial participants, though those patients were very ill and the effects might not have been from the supplement alone.

During pregnancy, cat's claw is possibly unsafe — it has a history of traditional use to end pregnancies, and we don't have solid safety data. Don't use it if you're pregnant.

While breastfeeding, there isn't enough information to know if it's safe, so you should avoid it then too.

Side effects, ingredient by ingredient Cat's Claw

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Cat's Claw.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs.
  • For scale: 963 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Double-check before starting if you take blood thinners or antiplatelet drugs (like warfarin or aspirin), blood pressure medications or calcium channel blockers, immunosuppressants, drugs that rely on CYP3A4 metabolism, or nirmatrelvir/ritonavir (Paxlovid). These are the medication types cat's claw may interact with at a Moderate severity level.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Cat's Claw Bark by Cedar Bear could be worth considering if you've done your homework on interactions and your doctor or pharmacist has cleared it — but the evidence for what it actually does isn't established yet. If you take blood thinners, blood pressure meds, immunosuppressants, or anything metabolized by your liver's CYP3A4 enzyme, check with us first.

Don't use it in pregnancy or while nursing.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2020.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Cat's Claw Bark, straight from the product label.

Brand Cedar Bear
Barcode (UPC) 834711000802
Net contents 30 mL; 1 fl. Oz.
Market status On market
Date entered into DSLD Sep 25, 2020
DSLD ID 237001
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Gluten Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Cat's Claw Bark by Cedar Bear, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
0.5 mL
Maximum serving Sizes:
0.5 mL
Servings per container
60
UPC/BARCODE
834711000802
IngredientAmount% DV
Proprietary Blend0.5 mL--
Cat's Claw0 NP--

Other ingredients: USP Grade Vegetable Glycerin, purified Water

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

Manufactured in the USA

True Alcohol Free Sugar Free Gluten Free

Vegan

Suggested/Recommended/Usage/Directions

Suggested use: .5 mL (10 drops) 1 to 3 times a day, or as needed. Shake well.

Precautions

Note: Consult your physician before use.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Seals/Symbols

GMP Good Manufacturing Practices K (Kosher)

Formula

K (Kosher)

Uncaria tomentosa

General Statements

Herbal Single

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Cat's Claw Bark by Cedar Bear label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Cat's Claw Bark label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Cat's Claw Bark by Cedar Bear

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size0.5 mL Dosage formLiquid Servings per container60 Amounts shown are per serving.

Proprietary Blend

0.5 mL per serving

Other (inactive) ingredients: USP Grade Vegetable Glycerin, Purified Water. These complete the product’s ingredient list but are not active constituents.

Interaction report

Cat's Claw Bark by Cedar Bear Drug Interactions

Want to check YOUR meds against Cat's Claw Bark?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
962Drugs
962 Moderate

Ingredients driving the most interactions

Cat's Claw 962

Individual Drug Interactions

The ingredients in Cat's Claw Bark interact with 962 drugs. Click any drug to see the details.

1 of the 1 ingredient in Cat's Claw Bark interact with drugs. Each result below shows which ingredient is responsible. Cat's Claw

Each ingredient & the kinds of drugs it affects

For each ingredient in Cat's Claw Bark with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Cat's Claw6 drug types · 962 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, cat's claw may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Cat's claw contains rhynchophylline and isorhynchophylline. Animal research suggests that these alkaloids can inhibit platelet aggregation. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, taking cat's claw with antihypertensive drugs might increase the risk of hypotension.
Cat's claw contains rhynchophylline. In vitro and animal research suggests that rhynchophylline can lower blood pressure. This interaction has not been reported in humans.

Likelihood Probable Evidence D
Calcium Channel Blockers

Theoretically, taking cat's claw with calcium channel blockers might increase the risk of hypotension.
Cat's claw contains various alkaloids, including rhynchophylline, isorhynchophylline, corynoxeine, and isocorynoxiene. Animal research suggests that these alkaloids can lower blood pressure by acting as calcium channel blockers. This interaction has not been reported in humans.

Likelihood Probable Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, cat's claw might increase or decrease the levels and effects of drugs metabolized by CYP3A4.
Cat's claw may affect the clearance of drugs metabolized by CYP3A4. In vitro research shows that cat's claw can inhibit CYP3A4 enzymes. In one case report, a patient taking cat's claw (at an unspecified dose) experienced increased serum levels of atazanavir, ritonavir, and saquinavir, all of which are CYP3A4 substrates. Levels returned to normal 15 days after discontinuation of the cat's claw supplement, suggesting inhibition of CYP3A4 by cat's claw. In contrast, animal research suggests that rhynchophylline, an alkaloid contained in cat's claw, induces CYP3A expression and accelerates the metabolism of nirmatrelvir, the active component in the nirmatrelvir/ritonavir combination product.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, cat's claw might interfere with immunosuppressive therapy.
In human and laboratory research, cat's claw has been shown to have immunostimulating activity. It stimulates phagocytosis and increases respiratory cellular activity and the mobility of leukocytes. Theoretically, this could interfere with the activity of immunosuppressant medications.

Likelihood Possible Evidence D
Nirmatrelvir/Ritonavir (Paxlovid)

Theoretically, cat's claw may decrease the levels of nirmatrelvir.
Cat's claw contains rhynchophylline. Animal research suggests that this alkaloid induces CYP3A expression, thereby accelerating the metabolism of nirmatrelvir, the active component in the nirmatrelvir/ritonavir combination product. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cat's Claw full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Cat's Claw Bark, from the product label.

Cedar Bear

See all Cedar Bear products
Name
Cedar Bear Naturales INC
Street Address
PO Box 158
City
Roosevelt
State
UT
ZipCode
84066
Phone Number
1-888-854-3727
Web Address
Cedarbear.com
Pharmacist Counseling Corner

Cat's Claw Bark by Cedar Bear: Common Questions

Does Cat's Claw Bark by Cedar Bear interact with any medications?
Yes. Based on its ingredients, Cat's Claw Bark has a known interaction with 962 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Cat's Claw Bark contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant?
No — cat's claw is rated possibly unsafe in pregnancy. It has a traditional history of being used to end pregnancies, and we don't have solid safety data. Talk to your doctor before considering it.
Is it safe while breastfeeding?
There isn't enough information to know either way. The safety data just isn't on file for breastfeeding, so it's best to avoid it and ask your pharmacist or doctor about alternatives.
What does cat's claw actually do? Does it work?
We don't have reliable evidence yet that cat's claw works for the conditions it's marketed for — hay fever, Alzheimer disease, asthma, osteoporosis, cancer, or chronic fatigue. That doesn't mean it's ineffective; the clinical research just hasn't established it one way or the other.
Are there any side effects I should know about?
In a cancer trial, some people experienced low blood cell counts and nerve-related problems, but those patients were very ill so we can't be sure the supplement caused them. Case reports have also linked cat's claw to kidney injury in a few people. It's generally well tolerated short-term in healthy people, but we don't have good long-term safety data.
What's in the liquid besides the active ingredient?
Vegetable glycerin and purified water — those are the inactive ingredients that carry the extract.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Cat's Claw Bark label
Go deeper

The Full Monographs Behind Cat's Claw Bark’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Cat's Claw

Interacts with 962 drugs

Cat's claw is a South American vine traditionally used for inflammation, joint pain, and immune support. Some small studies hint it may help with arthritis symptoms, but the overall evidence...

Read the full Cat's Claw monograph →
Sources

Sources & How We Checked

Cat's Claw Bark's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 16 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Cat's Claw 16 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  3. Sandoval M, Charbonnet RM, Okuhama NN, et al. Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection. Free Radic Biol Med 2000;29:71-78.
  4. Müller AC, Kanfer I. Potential pharmacokinetic interactions between antiretrovirals and medicinal plants used as complementary and African traditional medicines. Biopharm Drug Dispos. 2011;32(8):458-70. PubMed
  5. Sheng, Y., Bryngelsson, C., and Pero, R. W. Enhanced DNA repair, immune function and reduced toxicity of C-MED-100, a novel aqueous extract from Uncaria tomentosa. J Ethnopharmacol. 2000;69(2):115-126. PubMed
  6. Lamm, S., Sheng, Y., and Pero, R. W. Persistent response to pneumococcal vaccine in individuals supplemented with a novel water soluble extract of Uncaria tomentosa, C-Med-100. Phytomedicine 2001;8(4):267-274.
  7. Sheng, Y., Li, L., Holmgren, K., and Pero, R. W. DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study. Phytomedicine 2001;8(4):275-282.
  8. Chen, C. X., Jin, R. M., Li, Y. K., Zhong, J., Yue, L., Chen, S. C., and Zhou, J. Y. Inhibitory effect of rhynchophylline on platelet aggregation and thrombosis. Zhongguo Yao Li Xue.Bao. 1992;13(2):126-130.
  9. Flythe, J. E., Rueda, J. F., Riscoe, M. K., and Watnick, S. Silicate nephrolithiasis after ingestion of supplements containing silica dioxide. Am.J.Kidney Dis. 2009;54(1):127-130. PubMed
  10. Zhou, J. and Zhou, S. Antihypertensive and neuroprotective activities of rhynchophylline: the role of rhynchophylline in neurotransmission and ion channel activity. J.Ethnopharmacol. 10-28-2010;132(1):15-27. PubMed
  11. Zhou, J. Y. and Zhou, S. W. Isorhynchophylline: A plant alkaloid with therapeutic potential for cardiovascular and central nervous system diseases. Fitoterapia 2012;83(4):617-626. PubMed
  12. Hemingway, S. R. and Phillipson, J. D. Proceedings: Alkaloids from S. American species of Uncaria (Rubiaceae). J.Pharm.Pharmacol. 1974;26 Suppl:113P.
  13. Hilepo, J. N., Bellucci, A. G., and Mossey, R. T. Acute renal failure caused by 'cat's claw' herbal remedy in a patient with systemic lupus erythematosus. Nephron 1997;77(3):361. PubMed
  14. De Paula LCL, Fonseca F, Perazzo F, et al. Uncaria tomentosa (cat's claw) improves quality of life in patients with advanced solid tumors. J Altern Complement Med. 2015;21(1):22-30.
  15. Portalatin G, Shettigar S, Carrion-Rodriguez A, et al. Ketogenic-Diet Shake Containing Uncaria tomentosa-Associated Acute Interstitial Nephritis. Case Rep Nephrol Dial 2022;12(3):219-225.
  16. Lei S, Guo A, Lu J, et al. Activation of PXR causes drug interactions with Paxlovid in transgenic mice. Acta Pharm Sin B 2023;13(11):4502-4510. PubMed

See these in context on the Cat's Claw monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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