Quercetin + Aspirin, Caffeine, Codeine Phosphate
Aspirin, Caffeine, Codeine Phosphate brand name: Anacin w/ Codeine.
Aspirin, Caffeine, Codeine Phosphate falls into 4 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 reportQuercetin and Aspirin, Caffeine, Codeine Phosphate
These two interact in 4 distinct ways. Each one is explained separately below.
Why Are There 4 Interactions?
Quercetin interacts with whole categories of medication. Aspirin, Caffeine, Codeine Phosphate falls into 4 of those categories, so it can interact with Quercetin in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).
ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES
1 of 4Why this applies to Aspirin, Caffeine, Codeine Phosphate
Aspirin, Caffeine, Codeine Phosphate falls under ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES — the group Quercetin interacts with.
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.
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.
Here's the gist for this combination pill (aspirin, caffeine, and codeine). Your kidneys use a tiny doorway called OAT3 to help clear certain substances out of your body. In lab dish studies, quercetin appears to block that doorway. In theory, that could slow how quickly some of these ingredients leave your system, letting their levels creep up a bit.
If that happened, you might notice more of the usual effects, like extra drowsiness from the codeine, jitteriness from the caffeine, or stomach upset from the aspirin. But I want to be honest with you: this is only seen in test tubes so far, never reported in real people, and food amounts of quercetin almost certainly won't matter. If you take high-dose quercetin supplements, just run it by your pharmacist or doctor first.
- 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
- 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
ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES
2 of 4Aspirin, Caffeine, Codeine Phosphate also falls under ORGANIC ANION TRANSPORTER 1 (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.
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.
Here's the gist with this combo pill. Your kidneys use a little transporter called OAT1 to clear certain drugs, including the aspirin part of this medication, out through your urine. In lab dishes, quercetin can block that transporter. In theory, if aspirin is cleared more slowly, a bit more could hang around, which might nudge up aspirin-type effects like stomach upset, heartburn, or ringing in the ears.
That said, I want to be honest about the strength here. This is based only on test-tube and animal work, and it has never been reported in actual people. Food amounts of quercetin almost certainly don't matter; concentrated supplements are the real question. Before adding a high-dose quercetin supplement, just run it by your pharmacist or doctor.
- 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
CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES
3 of 4Aspirin, Caffeine, Codeine Phosphate also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.
In vitro research show that quercetin inhibits CYP2D6. This effect has not been reported in humans.
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.
Here's the wrinkle with this combo product: the codeine part is a prodrug. Your body uses an enzyme called CYP2D6 to turn codeine into morphine, which is what actually relieves pain. Quercetin has been shown in lab dishes to block that same enzyme. If that blocking happened in real life, you might convert less codeine into morphine, so you could get less pain relief rather than more side effects. The aspirin and caffeine pieces aren't really affected here.
The good news: this is only seen in test-tube studies, never confirmed in people, so I wouldn't lose sleep over it, especially with food amounts of quercetin. If you take high-dose supplements regularly, just mention it to your pharmacist or doctor.
- Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
- DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
4 of 4Aspirin, Caffeine, Codeine Phosphate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
A small clinical study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine (Neoral, Sandimmune), a substrate of CYP3A4. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) and quetiapine (Seroquel), substrates of CYP3A4. Other laboratory research also shows that quercetin inhibits CYP3A4. However, one clinical study shows that quercetin can increase the metabolism of midazolam, a substrate of CYP3A4, and decrease serum concentrations of midazolam by about 24% in some healthy individuals, suggesting possible induction of CYP3A4.
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.
Here's the thing about this combo pill: the part that interacts with quercetin is the codeine, and codeine is a bit unusual. It's a prodrug, meaning your liver has to convert it into morphine before it does much for pain. Most of that activation runs through an enzyme called CYP2D6, not CYP3A4, so the quercetin link here is honestly pretty weak and mostly theoretical (based on lab and animal work, not solid human studies on this exact medicine).
If quercetin nudged the CYP3A4 pathway at all, it could shift codeine a little in either direction, slightly more drowsiness and constipation, or slightly less pain relief. The aspirin and caffeine pieces aren't really affected. Food amounts of quercetin shouldn't matter. Before starting a high-dose supplement, just run it by your pharmacist or doctor.
- Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
- DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
- Choi JS, Choi BC, Choi KE. Effect of quercetin on the pharmacokinetics of oral cyclosporine. Am J Health Syst Pharm 2004;61:2406-9. PubMed
- Choi JS, Jo BW, Kim YC. Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin. Eur J Pharm Biopharm 2004;57:313-8. PubMed
- Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJ. Effect of quercetin on CYP3A activity in Chinese healthy participants. J Clin Pharmacol 2012;52(6):940-6. PubMed
- Zhao Q, Wei J, Zhang H. Effects of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. Xenobiotica 2019;49(5):563-8. PubMed
- Bhutani P, Rajanna PK, Paul AT. Impact of quercetin on pharmacokinetics of quetiapine: insights from in-vivo studies in wistar rats. Xenobiotica. 2020:1-7.
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Quercetin Also Interacts With Other Medications
Quercetin has 1,168 moderate known drug interactions in our database — the Aspirin, Caffeine, Codeine Phosphate one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Quercetin
We haven’t checked that one against Quercetin yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Quercetin. Pick one to open its full report.
See Every Supplement That Interacts With Aspirin, Caffeine, Codeine Phosphate
This page covers Quercetin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Codeine Phosphate page lists 398 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Danshen (major).
By severity: 17 major · 334 moderate · 47 minor.
From our pharmacist’s overview on the Aspirin, Caffeine, Codeine Phosphate page
“Anacin with Codeine combines aspirin, caffeine, and codeine, and each of the three picks up its own supplement problems, so this is a list worth real caution. Just over half of the 398 ingredients here, 202 of them, can add to aspirin's blood-thinning action and raise bleeding risk.”
Reviewed by 2 · Jul 18, 2026
Open the Aspirin, Caffeine, Codeine Phosphate interaction page
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 Aspirin, Caffeine, Codeine Phosphate 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:
Where Quercetin and Aspirin, Caffeine, Codeine 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.
#48 of 1,452 supplements looked up here in the last 7 days
#1,475 of 2,830 medications looked up here in the last 7 days
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.
About Quercetin
What is 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.
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.
No drugs match “”.
1,168 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Nifedipine ›
- Ibuprofen ›
- Aspirin ›
- Hydrocortisone ›
- Insulin (rdna) ›
- Naproxen ›
- Doxycycline ›
- Erythromycin ›
- Estradiol ›
- Minocycline ›
- Propranolol ›
- Tetracycline ›
- Lidocaine ›
- Ranitidine ›
- Hydrochlorothiazide ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Glyburide ›
- Insulin (pork) ›
- Triazolam ›
- Zopiclone ›
- Ciprofloxacin ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Isotretinoin ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Triamcinolone ›
- Apomorphine ›
- Budesonide ›
- Carbamazepine ›
- Ceftazidime ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Hydralazine ›
- Indomethacin ›
- Insulin (human) ›
- Miconazole ›
- Morphine Sulfate ›
- Salsalate ›
- Trimipramine ›
- Acyclovir ›
- Amphetamine ›
Showing 60 of 1,168 moderate interactions — see all 1,168 on the Quercetin page.
No interaction 1,661 drugs checked — show the list
We also checked Quercetin against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Docusate ›
- Hydroxyurea ›
- Sumatriptan ›
- Bupropion ›
- Amoxicillin ›
- Bendamustine ›
- Lamotrigine ›
- Gabapentin ›
- Pregabalin ›
- Azithromycin ›
- Methylene Blue ›
- Levothyroxine, Liothyronine ›
- Cyclopentolate ›
- Roxithromycin ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Pegunigalsidase Alfa-iwxj ›
- Daptomycin ›
- Hexobarbitone ›
- Levothyroxine Sodium ›
- Dexmethylphenidate ›
- Levetiracetam ›
- Factor 7a ›
- Carbidopa, Levodopa ›
- Thyroid Hormone ›
- Mitomycin ›
- Levodopa ›
- Ezetimibe ›
- Lenvatinib ›
- Phenylephrine ›
- Vancomycin ›
- Hethylphenidate Hcl ›
- Phentermine, Topiramate ›
- Bentoquatam ›
- Dirithromycin ›
- Procainamide ›
- Tenecteplase ›
- Hydroxychloroquine ›
- Amoxicillin, Clavulanate Potassium ›
- Azelaic Acid ›
- Dextrothyroxine ›
- Triptorelin ›
- Lomustine ›
- Sodium Valproate ›
- Tocainide ›
- Pizotifen ›
- Pentobarbitone ›
- Rocuronium ›
- Succimer ›
- Mitomycin C ›
- Lorazepam ›
- Paracetamol ›
- Halothane ›
- Gestodene ›
- Chenodiol ›
- Desflurane ›
Showing the 60 most looked-up of 1,661 medications checked with no known interaction — see the full Quercetin list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Aspirin, Caffeine, Codeine Phosphate Is Linked to Lower Levels of 4 Nutrients
Natural Medicines records Aspirin, Caffeine, Codeine Phosphate as a medicine that can lower these. This is not an interaction with Quercetin — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:
Read the full Aspirin, Caffeine, Codeine Phosphate nutrient depletion report ›
Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.
Taking Quercetin and Aspirin, Caffeine, Codeine Phosphate Together: Common Questions
Can you take Quercetin with Aspirin, Caffeine, Codeine Phosphate?
Why are there 4 interactions listed for Quercetin and Aspirin, Caffeine, Codeine Phosphate?
How serious is the Quercetin and Aspirin, Caffeine, Codeine Phosphate interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.