Drug & supplement interaction

Goldenseal + Oseltamivir Phosphate

Oseltamivir Phosphate brand name: Tamiflu.

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

Goldenseal has a minor interaction with Oseltamivir Phosphate. Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.

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

Goldenseal and Oseltamivir Phosphate

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

Minor

OSELTAMIVIR (Tamiflu)

Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.
In vitro evidence suggests that goldenseal reduces the formation of the active compound from the prodrug oseltamivir. The mechanism of action and clinical relevance is unclear.
Severity Minor 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 thing to know about Tamiflu (oseltamivir): it's a prodrug, meaning you swallow an inactive form that your body has to convert into the working antiviral. There's some early lab research suggesting goldenseal might slow that conversion. If less of the active drug gets made, the worry is that Tamiflu wouldn't fight the flu as well, so symptoms like fever, cough, body aches, and tiredness might stick around longer.

I'll be honest though: this is only test-tube evidence, and we don't really know if it plays out in actual people. It's rated as a minor, theoretical concern. Still, since you're taking Tamiflu to knock out the flu quickly, I'd just hold off on goldenseal during that stretch, or check with your pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu R, Tam TW, Mao J, et al. The effect of natural health products and traditional medicines on the activity of human hepatic microsomal-mediated metabolism of oseltamivir. J Pharm Pharm Sci 2010;13(1):43-55. 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

Goldenseal Also Interacts With Other Medications

Goldenseal has 1,236 moderate known drug interactions in our database — the Oseltamivir Phosphate one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,236 No known interaction 1,594 (incl. Oseltamivir Phosphate)
Taking anything else?

Check Another of Your Medications Against Goldenseal

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

From our Q&A

Questions About Goldenseal or Oseltamivir Phosphate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Goldenseal or Oseltamivir Phosphate, 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 Oseltamivir Phosphate

This page covers Goldenseal only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Oseltamivir Phosphate page lists 22 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), African Wild Potato (moderate), Banderol (moderate), Caffeic Acid (moderate) and Coffee Charcoal (moderate).

By severity: 1 major · 11 moderate · 10 minor.

From our pharmacist’s overview on the Oseltamivir Phosphate page

“Tamiflu (oseltamivir phosphate) only has about five days to do its job against the flu, so this list deserves a careful read, and the single major entry, activated charcoal, deserves it most. Charcoal can adsorb the drug and cut how much reaches your bloodstream, which is exactly what you cannot afford during a short antiviral course.”

Reviewed by 2 · Jul 18, 2026

Open the Oseltamivir Phosphate interaction page

One more smart check

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

We hold 1,726 real supplement products containing Goldenseal, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Goldenseal. Your product may carry other ingredients that interact with Oseltamivir Phosphate too, on top of Goldenseal — 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 Goldenseal and Oseltamivir Phosphate 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 Goldenseal
Top 25%

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

29 days ago today
Medication Oseltamivir Phosphate
Steady interest

#1,951 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 Goldenseal

What is Goldenseal?

Goldenseal
  • Digestive upset and diarrhea
  • Colds and respiratory infections
  • Sore throat and mouth sores
  • Skin and eye irritation (topical/traditional)
  • Antimicrobial support

Goldenseal is a popular North American herb that contains berberine, a compound studied for antimicrobial effects. However, strong human evidence for its many traditional uses is largely lacking, and it should be avoided during pregnancy and breastfeeding. Talk to a pharmacist or doctor before using it.

Read the full Goldenseal monograph & all interactions
Medication

About Oseltamivir

What Is Oseltamivir Used For?

Brand name: Tamiflu

Oseltamivir is used to treat acute, uncomplicated influenza A and B in patients 2 weeks of age and older who have had symptoms for no more than 48 hours. It is also used to prevent (prophylaxis) influenza A and B in patients 1 year of age and older.

Keep in mind: oseltamivir is not a substitute for your annual flu vaccine. It does not work against bacterial infections or illnesses caused by anything other than influenza viruses.

See full Oseltamivir drug information
Keep checking

Other Drugs & Goldenseal

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

0Major
1,236Moderate
0Minor
1,593No known interaction
1,236 Moderate 1,593 No interaction
Moderate

1,236 interactions

Showing 60 of 1,236 moderate interactions — see all 1,236 on the Goldenseal page.

No interaction 1,593 drugs checked — show the list

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

Showing the 60 most looked-up of 1,593 medications checked with no known interaction — see the full Goldenseal list.

See the full Goldenseal interactions page
See every supplement checked against Oseltamivir Phosphate, 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
Goldenseal monograph › Uses, safety, and every drug interaction in one place Oseltamivir Phosphate supplement interactions › Every supplement checked against Oseltamivir Phosphate, ranked by severity Oseltamivir 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 Goldenseal and Oseltamivir Phosphate Together: Common Questions

Can you take Goldenseal with Oseltamivir Phosphate?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Goldenseal and Oseltamivir Phosphate interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Oseltamivir Phosphate and Goldenseal?

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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.