Drug & supplement interaction

Spearmint + Peginterferon alfa-2b

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

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

Spearmint has a moderate interaction with Peginterferon alfa-2b. Theoretically, high doses of spearmint might increase the risk of liver damage when taken with hepatotoxic drugs.

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

Spearmint and Peginterferon alfa-2b

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Peginterferon alfa-2b

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

Theoretically, high doses of spearmint might increase the risk of liver damage when taken with hepatotoxic drugs.
Animal research suggests that drinking spearmint tea for 30 days can increase markers of liver damage, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and cause liver degeneration and necrosis, in a dose-dependent manner. This effect has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the simple version: Peg-Intron is already known to be tough on the liver, which is why your care team checks your liver enzymes (AST and ALT) while you're on it. Spearmint as a food or an occasional cup of tea isn't the concern here. But in animal studies, very large amounts of spearmint over weeks bumped up those same liver markers and caused some liver injury.

So the worry is mainly theoretical and tied to concentrated spearmint supplements, not your dinner or a normal mug of tea. The thought is that stacking two things that can stress the liver might add up. We haven't actually seen this happen in people. I wouldn't lose sleep over culinary spearmint, but please run any spearmint supplement past your pharmacist or doctor first, since your liver is already being watched closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Akdogan M, Ozguner M, Aydin G, Gokalp O. Investigation of biochemical and histopathological effects of Mentha piperita Labiatae and Mentha spicata Labiatae on liver tissue in rats. Hum Exp Toxicol 2004;23:21-8.

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

Spearmint Also Interacts With Other Medications

Spearmint has 578 moderate 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.

Moderate 578 No known interaction 2,252 (incl. Peginterferon alfa-2b)
Taking anything else?

Check Another of Your Medications Against Spearmint

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

Everything else you take

See Every Supplement That Interacts With Peginterferon alfa-2b

This page covers Spearmint 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), Siberian Cocklebur (major), Wine (major), Ashwagandha (moderate) and Black Cohosh (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 Spearmint as Part of a Dietary Supplement Product? Check It for Interactions

We hold 408 real supplement products containing Spearmint, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Spearmint. Your product may carry other ingredients that interact with Peginterferon alfa-2b too, on top of Spearmint — 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 Spearmint 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 Spearmint
Top 25%

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

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

#2,298 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 Spearmint

What is Spearmint?

Spearmint
  • Digestive upset and indigestion
  • Nausea
  • Hormonal acne and unwanted hair (PCOS-related)
  • Memory and focus
  • Mild stress and anxiety
  • Joint discomfort

Spearmint is a common culinary mint that is generally safe in food and tea amounts. Early research suggests possible benefits for digestion, mild hormone-related issues (such as excess facial hair in women), and memory, but the evidence is still limited. Talk to your pharmacist or doctor before using concentrated supplements, especially if you are pregnant or have a health condition.

Read the full Spearmint 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 & Spearmint

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

0Major
578Moderate
0Minor
2,251No known interaction
578 Moderate 2,251 No interaction
Moderate

578 interactions

Showing 60 of 578 moderate interactions — see all 578 on the Spearmint page.

No interaction 2,251 drugs checked — show the list

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

Showing the 60 most looked-up of 2,251 medications checked with no known interaction — see the full Spearmint list.

See the full Spearmint 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
Spearmint 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 Spearmint and Peginterferon alfa-2b Together: Common Questions

Can you take Spearmint with Peginterferon 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 Spearmint and Peginterferon 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 Peginterferon alfa-2b and Spearmint?

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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.