Drug & supplement interaction

Cat's Claw + Interferon Beta-1a

Interferon Beta-1a brand names: Rebif, Avonex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Cat's Claw and Interferon Beta-1a in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Cat's Claw and Interferon Beta-1a

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Interferon Beta-1a and Cat's Claw in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Cat's Claw safety at a glance

Cat's Claw overall Use caution Generally well tolerated short-term in healthy adults, but long-term safety is not well studied.
Pregnancy Possibly Unsafe When used orally. There is concern that cat's claw might be unsafe based on its traditional use as a contraceptive; avoid using. Read the full pregnancy detail
Breastfeeding Avoid Avoid while breastfeeding due to insufficient safety information.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Interferon Beta-1a and Cat's Claw? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Interferon Beta-1a

Interactions in our licensed database are recorded against drug classes, not just single drug names. Interferon Beta-1a is filed under 2 classifications — photosensitizing drugs, hepatotoxic drugs. Cat's Claw has documented interactions with 6 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antihypertensive drugs (moderate) and calcium channel blockers (moderate) — and none of Interferon Beta-1a’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Cat's Claw Does Interact With Other Medications

Cat's Claw has 962 moderate known drug interactions in our database — Interferon Beta-1a isn’t one of them. If you take anything else, check it against the full list below.

Moderate 962 No known interaction 1,868 (incl. Interferon Beta-1a)
Taking anything else?

Check Another of Your Medications Against Cat's Claw

Covers the 2,830 medications we’ve checked against Cat's Claw. Pick one to open its full report.

What to actually watch for

What Cat's Claw Itself Has Been Linked To

This is not an interaction — nothing below involves Interferon Beta-1a. It is the side-effect record for Cat's Claw on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Cat's Claw, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Kidney stones / Kidney problems Worth acting on Additional detail

    “Several case reports link cat's claw to kidney injury. A patient with systemic lupus erythematosus developed acute kidney failure after taking cat's claw, which improved upon its discontinuation. Another patient with a history of cancer who consumed keto-diet shakes containing cat's claw developed biopsy-confirmed acute interstitial nephritis requiring treatment with prednisone.”

    Cat's Claw · Natural Medicines adverse-effect record, reported in cancer.

    4 sources cited
    1. 40279. 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
    2. 111737. 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.
    3. 40244. 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
    4. 92502. 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.
  • A low platelet count / Anemia / A low white blood cell count Worth acting on Additional detail

    “In one clinical study of oral cat's claw, anemia occurred in 12% of patients and leukopenia and thrombocytopenia each occurred in 2% of patients. As the patients in this study had solid tumors with no further therapeutic options, it cannot be determined if any adverse effects were due to the course of disease or to cat's claw. No placebo was used in the study.”

    Cat's Claw · Natural Medicines adverse-effect record, reported in anemia.

    1 source cited
    1. 92502. 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.
  • Trouble sleeping / Tiredness Additional detail

    “In one clinical study of oral cat's claw, headache occurred in 2% of patients, fatigue and insomnia each occurred in 4% of patients, and neuropathy occurred in 8% of patients. As the patients in this study had solid tumors with no further therapeutic options, it cannot be determined if any adverse effects were due to the course of disease or to cat's claw. No placebo was used in the study.”

    Cat's Claw · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 92502. 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.
  • Constipation / Stomach pain Additional detail

    “Orally, cat's claw has been reported to cause nausea, vomiting, abdominal pain, abdominal distention, constipation, epigastric pain, and diarrhea in 2% to 10% of individuals in one clinical study. As the patients in this study had solid tumors with no further therapeutic options, it cannot be determined if any adverse effects were due to the course of disease or to cat's claw. No placebo was used in the study.”

    Cat's Claw · Natural Medicines adverse-effect record, reported in constipation.

    1 source cited
    1. 92502. 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.
  • Itching Additional detail

    “Orally, itchy skin lesions occurred rarely in one clinical study. As the patients in this study had solid tumors with no further therapeutic options, it cannot be determined if any adverse effects were due to the course of disease or to cat's claw. No placebo was used in the study.”

    Cat's Claw · Natural Medicines adverse-effect record, reported in solid tumors.

    1 source cited
    1. 92502. 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.

Showing the 10 most notable of 14 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Cat's Claw — expand a row for the licensed statement it rests on. We haven’t matched Interferon Beta-1a to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Interferon Beta-1a.

Special populations

Cat's Claw in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally. There is concern that cat's claw might be unsafe based on its traditional use as a contraceptive; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Cat's Claw or Interferon Beta-1a

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cat's Claw or Interferon Beta-1a, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Interferon Beta-1a

This page covers Cat's Claw only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Beta-1a page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Beta-1a page

“Siberian cocklebur, an herb tied to documented cases of liver failure, is the first name to know for anyone injecting interferon beta-1a (Rebif, Avonex) for multiple sclerosis. Interferon beta-1a can strain the liver on its own, which is why prescribers order routine liver blood tests, and 38 of the 57 supplements on file carry that sa…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Beta-1a interaction page

One more smart check

Taking Cat's Claw as Part of a Dietary Supplement Product? Check It for Interactions

We hold 910 real supplement products containing Cat's Claw, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cat's Claw. Even though Cat's Claw itself has no known interaction with Interferon Beta-1a, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cat's Claw and Interferon Beta-1a Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Cat's Claw
Top 25%

#230 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Interferon Beta-1a
Top half

#1,112 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Cat's Claw reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Cat's Claw and Interferon Beta-1a records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Cat's Claw

What is Cat's Claw?

Cat's Claw
  • Osteoarthritis and rheumatoid arthritis
  • Inflammation
  • Immune support
  • Digestive complaints
  • General wellness/tonic

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 is limited and not strong enough to confirm clear benefits. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Uncaria tomentosa · Rubiaceae · Bark and root · Capsules, tablets, liquid extracts/tinctures, tea

An interaction check asks whether these two react with each other — it does not ask whether Cat's Claw is a good idea for someone in your situation. Here is what our Cat's Claw record says about it on its own.

Cat's Claw: dosing

There is no official or well-established standard dose of cat's claw. The amount used in studies has varied depending on the type of product (such as a dried bark extract versus a standardized extract).The best approach is to follow the directions on the product label and not take more than recommended.

From our Cat's Claw monograph — the full record covers uses, side effects and every documented interaction.

Read the full Cat's Claw monograph & all interactions
Medication

About Interferon Beta-1a Intramuscular Injection

What Is Interferon Beta-1a Intramuscular Injection Used For?

Brand names: Rebif, Avonex

  • Interferon beta-1a intramuscular injection is used to treat adults with various forms of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control) including:

    • clinically isolated syndrome (CIS; nerve symptom episodes that last at least 24 hours),

    • relapsing-remitting forms (course of disease where symptoms flare up from time to time), or

    • secondary progressive forms (course of disease where relapses occur more often).

  • Interferon beta-1a is in a class of medications called immunomodulators. It works by decreasing inflammation and preventing nerve damage that may cause symptoms of multiple sclerosis.

Most-Reported Side Effects for Interferon Beta-1a

From FAERS, the FDA’s public side-effect reporting system (192,069 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Multiple sclerosis relapse 15,851 reports
Influenza like illness 13,253 reports
Fatigue 11,554 reports
Fall 10,604 reports
Multiple sclerosis 9,358 reports
See full Interferon Beta-1a Intramuscular Injection drug information
Keep checking

Other Drugs & Cat's Claw

Browse every other medication we’ve checked against Cat's Claw — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
962Moderate
0Minor
1,867No known interaction
962 Moderate 1,867 No interaction
Moderate

962 interactions

Showing 60 of 962 moderate interactions — see all 962 on the Cat's Claw page.

No interaction 1,867 drugs checked — show the list

We also checked Cat's Claw against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,867 medications checked with no known interaction — see the full Cat's Claw list.

See the full Cat's Claw interactions page
See every supplement checked against Interferon Beta-1a, ranked by severity
Evidence & sources

Cat's Claw References

The 16 references that drive our Cat's Claw monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Cat's Claw and Interferon Beta-1a Together: Common Questions

Is it safe to take Cat's Claw with Interferon Beta-1a?
We do not list a known interaction between Cat's Claw and Interferon Beta-1a. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Cat's Claw and Interferon Beta-1a combination checked?
Interactions in our licensed database are recorded against drug classes. Interferon Beta-1a is filed under 2 classifications, and Cat's Claw has documented interactions with 6 drug classes — none of Interferon Beta-1a's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Cat's Claw interact with any other medications?
Yes. Cat's Claw has 962 documented drug interactions in our database — Interferon Beta-1a is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Interferon Beta-1a interact with any supplements?
Yes. Interferon Beta-1a has documented interactions with 57 supplements in our database — Cat's Claw is not one of them. The Interferon Beta-1a interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Cat's Claw monograph Uses, safety profile, and every drug interaction in one place Interferon Beta-1a Intramuscular Injection drug information The full plain-English guide to this medication Interferon Beta-1a supplement interactions Every supplement checked against Interferon Beta-1a, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 16 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.