Drug & supplement interaction

Siberian Cocklebur + Peginterferon alfa-2b

Peginterferon alfa-2b brand names: Peg-Intron, ViraferonPeg.

Major Interaction
Medically reviewed by · Updated October 2026
The bottom line Major

Siberian Cocklebur has a major interaction with Peginterferon alfa-2b. Siberian cocklebur can adversely affect the liver.

Read the full interaction report
SeverityMajor
LikelihoodLikely
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Siberian Cocklebur and Peginterferon alfa-2b

Here is the interaction we found between these two, with the evidence behind it.

Major

HEPATOTOXIC DRUGS

Why this applies to Peginterferon alfa-2b

Peginterferon alfa-2b falls under HEPATOTOXIC DRUGS — the group Siberian Cocklebur interacts with.

Siberian cocklebur can adversely affect the liver. It has been linked to many cases of hepatotoxicity and some cases of liver failure. Theoretically, concomitant use with other potentially hepatotoxic drugs might increase the risk of developing liver damage. Some of these drugs include acarbose (Precose, Prandase), amiodarone (Cordarone), atorvastatin (Lipitor), azathioprine (Imuran), carbamazepine (Tegretol), cerivastatin (Baycol), diclofenac (Voltaren), felbamate (Felbatol), fenofibrate (TriCor), fluvastatin (Lescol), gemfibrozil (Lopid), isoniazid, itraconazole, (Sporanox), ketoconazole (Nizoral), leflunomide (Arava), lovastatin (Mevacor), methotrexate (Rheumatrex), nevirapine (Viramune), niacin, nitrofurantoin (Macrodantin), pioglitazone (Actos), pravastatin (Pravachol), pyrazinamide, rifampin (Rifadin), ritonavir (Norvir), rosiglitazone (Avandia), simvastatin (Zocor), tacrine (Cognex), tamoxifen, terbinafine (Lamisil), valproic acid, and zileuton (Zyflo).
Severity Major Likelihood Likely Evidence B

Well-controlled human studies have demonstrated the likely existence of this interaction.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the concern I'd raise with you: Siberian cocklebur can be hard on the liver. It has been tied to real cases of liver injury and even some cases of liver failure. Peginterferon alfa-2b can also stress the liver, and it's already used in people whose liver isn't fully healthy because of hepatitis C. Putting both together may stack up the risk.

What that might look like: yellowing of the skin or eyes, dark urine, belly pain on the right side, nausea, unusual tiredness, or worsening liver blood tests. Because this combination could be serious, I would not add cocklebur on your own. Please check with your doctor or pharmacist first, since they're already watching your liver closely during treatment.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gurley ES, Rahman M, Hossain MJ, et al. Fatal outbreak from consuming Xanthium strumarium seedlings during time of food scarcity in northeastern Bangladesh. PLoS One 2010 Mar 18;5(3):e9756. PubMed
  2. Turgut M, Alhan CC, Gurgoze M, et al. Carboxyatractyloside poisoning in humans. Ann Trop Paediatr 2005;25(2):125-34. PubMed
  3. Karabiber H, Almis H, Selimoglu MA, Yakinci C, Yilmaz S. Xanthium strumarium poisoning requiring liver transplantation. J Pediatr Gastroenterol Nutr. 2014;58(1):e6-9.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Siberian Cocklebur Also Interacts With Other Medications

Siberian Cocklebur has 663 major, known drug interactions in our database — the Peginterferon alfa-2b one above is one of them. If you take anything else, check it against the full list below.

Major 663 No known interaction 2,167 (incl. Peginterferon alfa-2b)
Taking anything else?

Check Another of Your Medications Against Siberian Cocklebur

Covers the 2,830 medications we’ve checked against Siberian Cocklebur. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Peginterferon alfa-2b

This page covers Siberian Cocklebur only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Peginterferon alfa-2b page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Wine (major), Ashwagandha (moderate), Black Cohosh (moderate) and Boldo (moderate).

By severity: 3 major · 35 moderate.

From our pharmacist’s overview on the Peginterferon alfa-2b page

“Someone taking peginterferon alfa-2b (Peg-Intron) is usually treating hepatitis C, so the liver is already the organ under strain, and all 38 supplement interactions on file for this drug pile additional liver stress on top of it. That earns genuine caution.”

Reviewed by 2 · Jul 18, 2026

Open the Peginterferon alfa-2b interaction page

One more smart check

Taking Siberian Cocklebur as Part of a Dietary Supplement Product? Check It for Interactions

We hold 84 real supplement products containing Siberian Cocklebur, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Siberian Cocklebur. Your product may carry other ingredients that interact with Peginterferon alfa-2b too, on top of Siberian Cocklebur — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Siberian Cocklebur and Peginterferon alfa-2b 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 Siberian Cocklebur
Top half

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

29 days ago today
Medication Peginterferon alfa-2b
Steady interest

#2,571 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.

Supplement

About Siberian Cocklebur

What is Siberian Cocklebur?

  • Nasal congestion and sinus problems
  • Allergic rhinitis (hay fever)
  • Headache
  • Skin conditions and itching
  • Joint and muscle discomfort

Siberian cocklebur is a fruit used in traditional Chinese and other Asian herbal medicine, mainly for nasal congestion, sinus issues, and allergies. Human evidence is very limited, and the plant contains naturally toxic compounds that can cause serious poisoning, so it should only be used under expert guidance, if at all.

Read the full Siberian Cocklebur monograph & all interactions
Medication

About Peginterferon Alfa-2b (PEG-Intron)

What Is Peginterferon Alfa-2b (PEG-Intron) Used For?

Brand names: Peg-Intron, ViraferonPeg

  • Peginterferon alfa-2b is used alone or in combination with ribavirin (a medication) to treat chronic (long-term) hepatitis C infection (swelling of the liver caused by a virus) in people who show signs of liver damage and who have not been treated with interferon alpha (medication similar to peginterferon alfa-2b) in the past. Peginterferon alfa-2b is in a class of medications called interferons. Peginterferon alfa-2b is a combination of interferon and polyethylene glycol, which helps the interferon stay active in your body for a longer period of time. Peginterferon alpha-2b works by decreasing the amount of hepatitis C virus (HCV) in the body. Peginterferon alfa-2b may not cure hepatitis C or prevent you from developing complications of hepatitis C such as cirrhosis (scarring) of the liver, liver failure, or liver cancer. Peginterferon alfa-2b may not prevent the spread of hepatitis C to other people.

See full Peginterferon Alfa-2b (PEG-Intron) drug information
Keep checking

Other Drugs & Siberian Cocklebur

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

663Major
0Moderate
0Minor
2,166No known interaction
663 Major 2,166 No interaction
Major

663 interactions

Showing 60 of 663 major interactions — see all 663 on the Siberian Cocklebur page.

No interaction 2,166 drugs checked — show the list

We also checked Siberian Cocklebur against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,166 medications checked with no known interaction — see the full Siberian Cocklebur list.

See the full Siberian Cocklebur interactions page
See every supplement checked against Peginterferon alfa-2b, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

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

Keep exploring
Siberian Cocklebur monograph › Uses, safety, and every drug interaction in one place Peginterferon alfa-2b supplement interactions › Every supplement checked against Peginterferon alfa-2b, ranked by severity Peginterferon Alfa-2b (PEG-Intron) drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Siberian Cocklebur and Peginterferon alfa-2b Together: Common Questions

Can you take Siberian Cocklebur with Peginterferon alfa-2b?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Siberian Cocklebur and Peginterferon alfa-2b interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

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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.