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Dietary supplement

Cat's Claw 175 mg Ingredients & Drug Interactions

by Nature's Way

Cat's Claw 175 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Cat's Claw 175 mg 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 175 mg is a dietary supplement by Nature's Way with 2 active ingredients. 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 Bark Extract. 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 175 mg by Nature's Way

Ask about any prescription or over-the-counter medication and we check it for interactions with Cat's Claw 175 mg by Nature's Way — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Cat's Claw 175 mg by Nature's Way

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 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 2 of its 2 active ingredients.
  • “Cat's Claw Bark Extract” is listed as a grouped ingredient — the label gives one combined amount (175 mg) without saying how much of each component you get.

Cat's Claw 175 mg contains two active ingredients. Cat's Claw is an herbal extract from the bark of a South American vine; it includes compounds called alkaloids (rhynchophylline and others) that appear to be responsible for its effects.

The product also lists Alkaloid as a separate ingredient, though we hold no detailed data for it. Three inactive ingredients — hypromellose, cellulose, and magnesium stearate — round out the capsule.

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: Supports immune function.
  • We looked for evidence on: Chronic fatigue syndrome (CFS), immune response, infection resistance, immune modulation.
  • The closest evidence on file: Cat's Claw is rated "Insufficient Reliable Evidence To Rate" for Chronic fatigue syndrome (CFS) (Natural Medicines).

The evidence for cat's claw is not yet established in the data we hold. It's been studied for allergic rhinitis (hay fever), Alzheimer disease, asthma, osteoporosis, cancer, and chronic fatigue syndrome, but all those studies show insufficient reliable evidence to rate whether it actually works.

That doesn't mean it doesn't; it means we don't yet know.

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 by healthy adults, but how safe it is over months or years hasn't been studied much. In one clinical study of patients with advanced tumors, a small number experienced blood count changes (anemia in 12%, low white blood cells and low platelets each in 2%), headache in 2%, and fatigue, insomnia, or nerve damage in a few others — though it's unclear whether cat's claw or the underlying disease caused these.

Several case reports link cat's claw to kidney injury, including acute kidney failure in one person with lupus and acute kidney inflammation in another. The safety data advises against cat's claw during pregnancy (because it was traditionally used as an abortifacient and safety is unknown) and while breastfeeding due to insufficient safety information.

If you're pregnant, planning to become pregnant, or breastfeeding, talk with your doctor or pharmacist before use.

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.

Before you take Cat's Claw 175 mg, double-check with your pharmacist if you're on blood thinners (warfarin, apixaban, or aspirin), blood pressure medications, immune-suppressing drugs, or the antiviral Paxlovid. Also check if you take any drug that goes through the liver enzyme CYP3A4 — that's a large group and the tool below will catch it.

Altogether, these interactions span 948 individual medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Cat's Claw 175 mg is generally well tolerated short-term, but it interacts with blood thinners, blood pressure drugs, many medications your liver processes, immune-suppressing drugs, and Paxlovid. If you take any medications — especially for blood pressure, clotting, or immunity — check them with the tool below before you start.

Pregnant or breastfeeding? Skip this one.

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

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2025.

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 175 mg, straight from the product label.

Brand Nature's Way
Barcode (UPC) 033674607008
Net contents 60 Vegan Capsule(s)
Market status On market
Date entered into DSLD Sep 25, 2025
DSLD ID 337243
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free, Dairy 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 175 mg by Nature's Way, 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:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
033674607008
IngredientAmount% DV
Cat's Claw Bark Extract175 mg--
Cat's Claw160 mg--
Alkaloid7 mg--

Other ingredients: Hypromellose, Cellulose, Magnesium Stearate

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.
Formula

Supports immune function with Cat's Claw extract standardized to 4% alkaloids (7 mg per serving)

Cat's Claw 175 mg extract per serving

Formulation

Botanicals are sourced where they grow best Made with the quality you trust

Gluten free. No wheat, soy, dairy, gelatin, or artificial colors or flavors.

Bottled and tested in the USA

Vegan Gelatin Free

Vegan Gelatin Free

Premium extract Supports Immune function Plant powered

General Statements

Explore more products at naturesway.com

Bottle made from 50% post-consumer recycled plastic

Brand IP Statement(s)

Copyright 2024 Nature's Way Brands, LLC

Seals/Symbols

Vegan Gelatin Free

FDA Disclaimer Statement

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

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommendation: Adults take 1 capsule twice daily with water between meals.

Precautions

Warning: Do not use if you are pregnant, nursing, or attempting to become pregnant. If you are taking any medications, consult a healthcare professional before use.

Keep out of reach of children.

Safety sealed with inner seal. Do not use if seal is broken or missing.

Storage

Keep tightly closed. Store at room temperature. Avoid excessive heat and direct sunlight.

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

See for yourself

Cat's Claw 175 mg by Nature's Way label

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

Cat's Claw 175 mg 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 175 mg by Nature's Way

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Cat's Claw Bark Extract

Interacts with
962 drugs
175 mg per serving

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 arth...

Cat's Claw Bark Extract monograph & interactions
  • › Alkaloid

Cat's Claw

Interacts with
962 drugs
160 mg per serving

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 arth...

Cat's Claw monograph & interactions

Other (inactive) ingredients: Hypromellose, Cellulose, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Cat's Claw 175 mg by Nature's Way Drug Interactions

Want to check YOUR meds against Cat's Claw 175 mg?

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 Bark Extract 962

Individual Drug Interactions

The ingredients in Cat's Claw 175 mg interact with 962 drugs. Click any drug to see the details.

1 of the 2 ingredients in Cat's Claw 175 mg interact with drugs. Each result below shows which ingredient is responsible. Cat's Claw Bark Extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Cat's Claw 175 mg 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 Claw Bark Extract6 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 Bark Extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Cat's Claw 175 mg, from the product label.

Nature's Way

See all Nature's Way products
Name
Nature's Way Brands, LLC
City
Green Bay
State
WI
ZipCode
54311
Phone Number
1-800-962-8873
Web Address
naturesway.com
Pharmacist Counseling Corner

Cat's Claw 175 mg by Nature's Way: Common Questions

Does Cat's Claw 175 mg by Nature's Way interact with any medications?
Yes. Based on its ingredients, Cat's Claw 175 mg 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 175 mg contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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 or breastfeeding?
No — the safety data advises against it. Cat's claw was traditionally used to cause miscarriage and we don't have enough safety information for pregnancy or while breastfeeding. Talk with your doctor or pharmacist about whether it's right for you.
Does cat's claw actually work for the conditions it lists?
The evidence isn't established yet in the data we hold. It's been studied for conditions like hay fever, asthma, and Alzheimer disease, but so far there's insufficient reliable evidence to say whether it works. That doesn't mean it doesn't — just that we don't know yet.
What are the side effects I should watch for?
Short-term, most people tolerate it well. In one study of advanced-cancer patients, a few experienced blood count drops, headache, fatigue, insomnia, or nerve damage — though it's hard to know if cat's claw caused them. Several case reports link it to kidney injury, so if you have kidney problems or lupus, mention this supplement to your doctor before starting.
How long is it safe to take cat's claw?
Short-term safety looks fine in healthy adults, but we don't have good data on how safe it is if you take it for months or years. Talk with your pharmacist about how long you're planning to use it.
What does cat's claw actually do?
Cat's claw is a South American plant extract that contains alkaloid compounds. Research suggests it may stimulate your immune system and lower blood pressure — which is why it interacts with blood pressure medications and immune-suppressing drugs — but whether those effects actually help treat any condition isn't yet proven in the data we hold.

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

Not sure if Cat's Claw 175 mg is safe with your meds?

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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 175 mg label
Go deeper

The Full Monographs Behind Cat's Claw 175 mg’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 175 mg'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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