Drug & supplement interaction

Quercetin + Oxaprozin

Oxaprozin brand name: Daypro.

Moderate Interaction
The bottom line Moderate

Oxaprozin falls into 2 drug categories that Quercetin can interact with; the most serious is rated moderate. Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Quercetin and Oxaprozin

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Quercetin interacts with whole categories of medication. Oxaprozin falls into 2 of those categories, so it can interact with Quercetin in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES

1 of 2

Why this applies to Oxaprozin

Oxaprozin falls under ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES — the group Quercetin interacts with.

Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT3, with half-maximal inhibitory concentration (IC50) values as low as 0.75 mcM. So far, this interaction 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 short version: your kidneys use a little transporter called OAT3 to help clear certain drugs out of your body. In lab and test-tube studies, quercetin appears to block OAT3. Since oxaprozin is partly handled by this pathway, the theory is that high-dose quercetin could slow its removal and let a bit more build up.

If that happened, you might notice the usual NSAID side effects a little more strongly, things like stomach upset, heartburn, fluid retention, higher blood pressure, or kidney strain. I want to be honest though: this has only been seen in lab studies, never reported in real people, so it's mostly theoretical. Food amounts of quercetin almost certainly don't matter; concentrated supplements are the question mark. Just check with your pharmacist or doctor before pairing them.

References
  1. Li C, Wang X, Bi Y, et al. Potent Inhibitors of Organic Anion Transporters 1 and 3 From Natural Compounds and Their Protective Effect on Aristolochic Acid Nephropathy. Toxicol Sci. 2020;175(2):279-291. PubMed
  2. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. PubMed
Moderate

ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES

2 of 2

Oxaprozin also falls under ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES.

Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM. So far, this interaction 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 gist with oxaprozin (Daypro) and quercetin. Your kidneys use a little transporter called OAT1 to help clear certain drugs out of your body. In test tube studies, quercetin appears to block that transporter. If that same effect happened in people, oxaprozin could leave your system a bit more slowly and build up, which might mean stronger effects and more of the usual NSAID side effects like stomach upset, heartburn, fluid retention, raised blood pressure, or kidney strain.

That said, this is purely theoretical right now, based only on lab data, and it has never been reported in real patients. Food amounts of quercetin are very unlikely to matter. Before starting a high-dose supplement, just run it by your pharmacist or doctor.

References
  1. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. 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

Quercetin Also Interacts With Other Medications

Quercetin has 1,168 moderate known drug interactions in our database — the Oxaprozin one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Quercetin

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

From our Q&A

Questions About Quercetin or Oxaprozin

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

This page covers Quercetin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Oxaprozin page lists 52 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Siberian Cocklebur (major) and Wine (major).

By severity: 5 major · 35 moderate · 12 minor.

From our pharmacist’s overview on the Oxaprozin page

“I would put oxaprozin (Daypro), a long-acting NSAID prescribed for arthritis pain, in the read-carefully category. The interactions that concern me most pile onto the drug's own weak spots: alcohol, meaning the beer and wine entries below, raises the odds of stomach bleeding on any NSAID, and several kidney-stressing herbs can deepen t…”

Reviewed by 2 · Jul 18, 2026

Open the Oxaprozin interaction page

One more smart check

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

We hold 4,589 real supplement products containing Quercetin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Quercetin. Your product may carry other ingredients that interact with Oxaprozin too, on top of Quercetin — 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 Quercetin and Oxaprozin 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 Quercetin
Top 5%

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

29 days ago today
Medication Oxaprozin
Steady interest

#2,774 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 Quercetin

What is Quercetin?

Quercetin
  • Seasonal allergies
  • Antioxidant support
  • Heart and blood pressure health
  • Anti-inflammatory support
  • Immune support
  • Exercise recovery

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood pressure, and inflammation, strong human evidence is limited for most uses. It is generally well tolerated in food amounts, but talk to your pharmacist or doctor before taking high-dose supplements.

Read the full Quercetin monograph & all interactions
Medication

About Oxaprozin

What Is Oxaprozin Used For?

Brand name: Daypro

Oxaprozin treats the signs and symptoms of osteoarthritis, rheumatoid arthritis, and juvenile rheumatoid arthritis — reducing joint pain, swelling, and stiffness. These uses are shared across available oral formulations, including Coxanto capsules, Oxaprozin capsules, and Oxaprozin tablets (including Daypro).

Juvenile rheumatoid arthritis dosing for children ages 6 to 16 is weight-based and has been studied with both the capsule and tablet formulations.

See full Oxaprozin drug information
Keep checking

Other Drugs & Quercetin

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

0Major
1,168Moderate
0Minor
1,661No known interaction
Moderate

1,168 interactions

Showing 60 of 1,168 moderate interactions — see all 1,168 on the Quercetin page.

No interaction 1,661 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Quercetin and Oxaprozin Together: Common Questions

Can you take Quercetin with Oxaprozin?
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.
Why are there 2 interactions listed for Quercetin and Oxaprozin?
Oxaprozin belongs to more than one drug category, and Quercetin interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Quercetin and Oxaprozin 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 Oxaprozin and Quercetin?

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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.