Drug & supplement interaction

Green Tea + Interferon Alfa-2b

Interferon Alfa-2b brand names: Rebetron, Intron A, Viraferon.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Green Tea has a moderate interaction with Interferon Alfa-2b. Theoretically, concomitant use might have additive adverse hepatotoxic effects.

Read the full interaction report
SeverityModerate
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Green Tea and Interferon Alfa-2b

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Interferon Alfa-2b

Interferon Alfa-2b falls under HEPATOTOXIC DRUGS — the group Green Tea interacts with.

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
Green tea extract supplements have been linked to several cases of hepatotoxicity and might have additive hepatotoxic effects with other drugs..
Severity Moderate Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the thing about combining green tea with Interferon Alfa-2b: both can be tough on your liver. Interferon itself is known to sometimes cause liver inflammation and raise liver enzymes, which is why your doctor watches your bloodwork closely during treatment. Concentrated green tea extract supplements (not your morning cup of tea) have been linked in rare cases to liver injury too. Stack them together and there's a theoretical chance the strain on your liver could add up.

I want to be honest though, this concern rests on scattered, anecdotal reports, not strong proof, and it's considered unlikely. Drinking green tea as a beverage is very different from taking high-dose extract pills. Since your liver is already the focus here, just run any green tea supplement past your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Bonkovsky HL. Hepatotoxicity associated with supplements containing Chinese green tea (Camellia sinensis). Ann Intern Med 2006;144:68-71.
  2. Gloro R, Hourmand-Ollivier I, Mosquet B, et al. Fulminant hepatitis during self-medication with hydroalcoholic extract of green tea. Eur J Gastroenterol Hepatol 2005;17:1135-7. PubMed
  3. Jimenez-Saenz M, Martinez-Sanchez, MDC. Acute hepatitis associated with the use of green tea infusions. J Hepatol 2006;44:616-9. PubMed
  4. Javaid, A. and Bonkovsky, H. L. Hepatotoxicity due to extracts of Chinese green tea (Camellia sinensis): a growing concern. J Hepatol 2006;45(2):334-335. PubMed
  5. Martinez-Sierra, C., Rendon, Unceta P., and Martin, Herrera L. [Acute hepatitis after green tea ingestion]. Med Clin (Barc.) 6-17-2006;127(3):119.
  6. Molinari, M., Watt, K. D., Kruszyna, T., Nelson, R., Walsh, M., Huang, W. Y., Nashan, B., and Peltekian, K. Acute liver failure induced by green tea extracts: case report and review of the literature. Liver Transpl. 2006;12(12):1892-1895. PubMed
  7. Federico, A., Tiso, A., and Loguercio, C. A case of hepatotoxicity caused by green tea. Free Radic.Biol Med 8-1-2007;43(3):474. PubMed
  8. Sarma, D. N., Barrett, M. L., Chavez, M. L., Gardiner, P., Ko, R., Mahady, G. B., Marles, R. J., Pellicore, L. S., Giancaspro, G. I., and Low, Dog T. Safety of green tea extracts : a systematic review by the US Pharmacopeia. Drug Saf 2008;31(6):469-484. PubMed
  9. Rohde, J., Jacobsen, C., and Kromann-Andersen, H. [Toxic hepatitis triggered by green tea]. Ugeskr.Laeger 1-17-2011;173(3):205-206.
  10. Yellapu, R. K., Mittal, V., Grewal, P., Fiel, M., and Schiano, T. Acute liver failure caused by 'fat burners' and dietary supplements: a case report and literature review. Can.J.Gastroenterol. 2011;25(3):157-160. PubMed
  11. Health Canada. Health Product Info Watch. October 2016; 5-6. Available at: http://www.hc-sc.gc.ca/dhp-mps/medeff/bulletin/hpiw-ivps_2016-10-eng.php#a15.
  12. Oketch-Rabah HA, Roe AL, Rider CV, et al. United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicol Rep. 2020;7:386-402. PubMed
  13. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed

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

Green Tea Also Interacts With Other Medications

Green Tea has 13 major, 904 moderate, 375 minor known drug interactions in our database — the Interferon Alfa-2b one above is one of them. If you take anything else, check it against the full list below.

Major 13 Moderate 904 Minor 375 No known interaction 1,538 (incl. Interferon Alfa-2b)
Taking anything else?

Check Another of Your Medications Against Green Tea

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

From our Q&A

Questions About Green Tea or Interferon Alfa-2b

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Green Tea or Interferon Alfa-2b, 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 Alfa-2b

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Alfa-2b 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 Alfa-2b page

“People taking interferon alfa-2b (Intron A, Rebetron) are usually treating hepatitis or a cancer, so the liver may already be under strain, and that is exactly where most of this list points. Of the 57 supplements on file, 38 can add to liver stress, and all three major-rated interactions sit in that group: Siberian cocklebur, which ha…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Alfa-2b interaction page

One more smart check

Taking Green Tea as Part of a Dietary Supplement Product? Check It for Interactions

We hold 9,084 real supplement products containing Green Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Green Tea. Your product may carry other ingredients that interact with Interferon Alfa-2b too, on top of Green Tea — 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 Green Tea and Interferon 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 Green Tea
Top 5%

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

29 days ago today
Medication Interferon Alfa-2b
Top half

#1,348 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 Green Tea

What is Green Tea?

Green Tea
  • Antioxidant support
  • Weight loss
  • Heart health
  • Mental alertness
  • Cancer risk reduction

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different story—they may help modestly with weight or heart health for some, but high doses have been linked to rare liver problems. Talk to your pharmacist or doctor before taking green tea supplements, especially if you have liver concerns or are pregnant.

Read the full Green Tea monograph & all interactions
Medication

About Interferon Alfa-2b Injection

What Is Interferon Alfa-2b Injection Used For?

Brand names: Rebetron, Intron A, Viraferon

  • Interferon alfa-2b injection is used to treat a number of conditions.

  • Interferon alfa-2b injection is used

    • alone or in combination with ribavirin (Copegus, Rebetol, Ribasphere) to treat chronic (long-term) hepatitis C infection (swelling of the liver caused by a virus) in people who show signs of liver damage,

    • to treat chronic hepatitis B infection (swelling of the liver caused by a virus) in people who show signs of liver damage,

    • to treat hairy cell leukemia (a white blood cell cancer),

    • to treat genital warts,

    • to treat Kaposi's sarcoma (a type of cancer that causes abnormal tissue to grow on different parts of the body) related to acquired immunodeficiency syndrome (AIDS),

    • to treat malignant melanoma (a cancer that begins in certain skin cells) in certain people who have had surgery to remove the cancer,

    • along with another medication to treat follicular non-Hodgkin's lymphoma (NHL; a slow-growing blood cancer).

  • Interferon alfa-2b is in a class of medications called immunomodulators. Interferon alfa-2b works to treat hepatitis C virus (HCV) and hepatitis B virus (HBV) by decreasing the amount virus in the body. Interferon alfa-2b may not cure hepatitis B or hepatitis C or prevent you from developing complications from these infections such as cirrhosis (scarring) of the liver, liver failure, or liver cancer. It also may not prevent the spread of hepatitis B or C to other people. It is not known exactly how interferon alfa-2b works to treat cancer or genital warts.

See full Interferon Alfa-2b Injection drug information
Keep checking

Other Drugs & Green Tea

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

13Major
904Moderate
375Minor
1,537No known interaction
13 Major 904 Moderate 375 Minor 1,537 No interaction
Major

13 interactions

Moderate

904 interactions

Showing 60 of 904 moderate interactions — see all 904 on the Green Tea page.

Minor

375 interactions

Showing 60 of 375 minor interactions — see all 375 on the Green Tea page.

No interaction 1,537 drugs checked — show the list

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

Showing the 60 most looked-up of 1,537 medications checked with no known interaction — see the full Green Tea list.

See the full Green Tea interactions page
See every supplement checked against Interferon 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
Green Tea monograph › Uses, safety, and every drug interaction in one place Interferon Alfa-2b supplement interactions › Every supplement checked against Interferon Alfa-2b, ranked by severity Interferon Alfa-2b Injection 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 Green Tea and Interferon Alfa-2b Together: Common Questions

Can you take Green Tea with Interferon Alfa-2b?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Green Tea and Interferon Alfa-2b interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Interferon Alfa-2b and Green Tea?

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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.