Drug & supplement interaction

Uva Ursi + Oseltamivir Phosphate

Oseltamivir Phosphate brand name: Tamiflu.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Uva Ursi and Oseltamivir Phosphate 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Uva Ursi and Oseltamivir Phosphate

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 Oseltamivir Phosphate and Uva Ursi 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.

Uva Ursi safety at a glance

Uva Ursi overall Use caution May be used short-term but can be toxic in high doses or with prolonged use.
Pregnancy Likely Unsafe When used orally. Uva ursi can have oxytocic effects, increasing the speed of labor; avoid using. Read the full pregnancy detail
Breastfeeding Avoid Not enough safety information, so avoid while breastfeeding.

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 Oseltamivir Phosphate and Uva Ursi? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Oseltamivir Phosphate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Oseltamivir Phosphate is filed under 3 classifications — including organic anion transporter 1 (oat1) substrates, oral drugs. Uva Ursi has documented interactions with 6 drug classes — the most serious being cytochrome p450 2c19 (cyp2c19) substrates (moderate), cytochrome p450 3a4 (cyp3a4) substrates (moderate) and glucuronidated drugs (moderate) — and none of Oseltamivir Phosphate’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

Uva Ursi Does Interact With Other Medications

Uva Ursi has 740 moderate, 63 minor known drug interactions in our database — Oseltamivir Phosphate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 740 Minor 63 No known interaction 2,027 (incl. Oseltamivir Phosphate)
Taking anything else?

Check Another of Your Medications Against Uva Ursi

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

What to actually watch for

No Interaction Found — But Data Suggests Uva Ursi and Oseltamivir Phosphate May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Vomiting / Nausea reported in 8.6% of FDA reports for Oseltamivir Phosphate Additional detail

    Uva Ursi

    “Orally, uva ursi may cause nausea, vomiting, diarrhea, and stomach upset. It can also irritate the gastrointestinal tract (19).”

    Uva Ursi · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 92148. de Arriba SG, Naser B, Nolte KU. Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations. Int J Toxicol. 2013;32(6):442-453.
    2. 19. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

    Oseltamivir Phosphate

    Listed in the ADVERSE REACTIONS section of the FDA label for Oseltamivir Phosphate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Uva Ursi but not commonly for Oseltamivir Phosphate: shortness of breath, stomach upset, seizures and diarrhea.

Effects for Oseltamivir Phosphate come from the ADVERSE REACTIONS section of its FDA label; effects for Uva Ursi come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 24,283 voluntary FDA FAERS reports for Oseltamivir Phosphate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Uva Ursi in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When used orally. Uva ursi can have oxytocic effects, increasing the speed of labor; 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 Uva Ursi 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 Uva Ursi 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 Uva Ursi 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 Uva Ursi as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,423 real supplement products containing Uva Ursi, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Uva Ursi. Even though Uva Ursi itself has no known interaction with Oseltamivir Phosphate, 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 Uva Ursi 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 Uva Ursi
Top 25%

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

29 days ago today
Medication Oseltamivir Phosphate
Steady interest

#1,622 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 Uva Ursi reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Uva Ursi and Oseltamivir Phosphate 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 Uva Ursi

What is Uva Ursi?

Uva Ursi
  • Urinary tract infections
  • Urinary discomfort
  • Mild diuretic
  • Kidney stones
  • Skin conditions

Uva ursi is a traditional herb used mainly for urinary tract infections, and its leaves contain a compound called arbutin that may have antimicrobial effects in the urine. Evidence in people is limited, and because high doses or long-term use may be harmful to the liver and could be toxic, it should only be used short-term and with guidance from a healthcare professional. Avoid it during pregnancy and breastfeeding.

Arctostaphylos uva-ursi · Ericaceae · Leaves · Tea, capsules, tablets, liquid extracts, tinctures

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

Uva Ursi: dosing

There is no well-established standard dose of uva ursi. Many products are standardized to a certain percentage of arbutin, and the right amount depends on the specific product.Because of toxicity concerns, uva ursi should only be used for a short time and not repeatedly throughout the year.

From our Uva Ursi monograph — the full record covers uses, side effects and every documented interaction.

Read the full Uva Ursi 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.

Most-Reported Side Effects for Oseltamivir Phosphate

From FAERS, the FDA’s public side-effect reporting system (24,283 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Vomiting 2,082 reports
Nausea 1,575 reports
Influenza 1,197 reports
Diarrhea 1,044 reports
Dyspnea 1,012 reports
See full Oseltamivir drug information
Keep checking

Other Drugs & Uva Ursi

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

0Major
740Moderate
63Minor
2,026No known interaction
740 Moderate 63 Minor 2,026 No interaction
Moderate

740 interactions

Showing 60 of 740 moderate interactions — see all 740 on the Uva Ursi page.

Minor

63 interactions

Showing 60 of 63 minor interactions — see all 63 on the Uva Ursi page.

No interaction 2,026 drugs checked — show the list

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

Showing the 60 most looked-up of 2,026 medications checked with no known interaction — see the full Uva Ursi list.

See the full Uva Ursi interactions page
See every supplement checked against Oseltamivir Phosphate, ranked by severity
Evidence & sources

Uva Ursi References

The 8 references that drive our Uva Ursi 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. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Wang L, Del Priore LV. Bull's-eye maculopathy secondary to herbal toxicity from uva ursi. Am J Ophthalmol 2004;137:1135-7. PubMed
  5. Beaux, D., Fleurentin, J., and Mortier, F. Effect of extracts of Orthosiphon stamineus Benth, Hieracium pilosella L., Sambucus nigra L. and Arctostaphylos uva-ursi (L.) Spreng. in rats. Phytother.Res 1999;13(3):222-225.
  6. de Arriba SG, Naser B, Nolte KU. Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations. Int J Toxicol. 2013;32(6):442-453.
  7. Park JB, Kim D, Min JS, et al. Identification and characterization of in vitro inhibitors against UDP-glucuronosyltransferase 1A1 in uva-ursi extracts and evaluation of in vivo uva-ursi-drug interactions. Food Chem Toxicol. 2018;120:651-661. PubMed
  8. Chauhan B, Yu C, Krantis A, et al. In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein. Can J Physiol Pharmacol. 2007;85(11):1099-107.

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 Uva Ursi and Oseltamivir Phosphate Together: Common Questions

Is it safe to take Uva Ursi with Oseltamivir Phosphate?
We do not list a known interaction between Uva Ursi and Oseltamivir Phosphate. 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.
Do Uva Ursi and Oseltamivir Phosphate have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Uva Ursi and Oseltamivir Phosphate combination checked?
Interactions in our licensed database are recorded against drug classes. Oseltamivir Phosphate is filed under 3 classifications, and Uva Ursi has documented interactions with 6 drug classes — none of Oseltamivir Phosphate'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 Uva Ursi interact with any other medications?
Yes. Uva Ursi has 803 documented drug interactions in our database — Oseltamivir Phosphate 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 Oseltamivir Phosphate interact with any supplements?
Yes. Oseltamivir Phosphate has documented interactions with 22 supplements in our database — Uva Ursi is not one of them. The Oseltamivir Phosphate 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

Uva Ursi monograph Uses, safety profile, and every drug interaction in one place Oseltamivir drug information The full plain-English guide to this medication Oseltamivir Phosphate supplement interactions Every supplement checked against Oseltamivir Phosphate, 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 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Oseltamivir Phosphate and Uva Ursi?

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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.