Quercetin + Hydrochlorothiazide, Pindolol
Hydrochlorothiazide, Pindolol brand name: Viskazide.
Hydrochlorothiazide, Pindolol falls into 4 drug categories that Quercetin can interact with; the most serious is rated moderate. Theoretically, taking quercetin with antihypertensive drugs might increase the risk of hypotension.
Read the full interaction reportQuercetin and Hydrochlorothiazide, Pindolol
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. Hydrochlorothiazide, Pindolol 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).
ANTIHYPERTENSIVE DRUGS
1 of 4Why this applies to Hydrochlorothiazide, Pindolol
Hydrochlorothiazide, Pindolol falls under ANTIHYPERTENSIVE DRUGS — the group Quercetin interacts with.
Quercetin can modestly decrease blood pressure in people with mild hypertension. Theoretically, it might have additive blood pressure lowering effects when used with antihypertensive drugs.
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.
Viskazide combines two blood pressure medicines: hydrochlorothiazide (a water pill) and pindolol (a beta-blocker). Both work to bring your blood pressure down. Here's the thing about quercetin: in some studies it slightly lowered blood pressure on its own. So when you stack it on top of medicines already doing that job, the effects could add up and push your blood pressure a little too low.
If that happens, you might feel dizzy, lightheaded, tired, or a bit faint, especially when you stand up quickly. Keep in mind this concern is mostly theoretical and the supporting evidence is modest. Food amounts of quercetin are very unlikely to matter, but concentrated supplements are worth a chat with your pharmacist or doctor first.
- Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr 2007;137:2405-11.
- Larson A, Witman MA, Guo Y, et al. Acute, quercetin-induced reductions in blood pressure in hypertensive individuals are not secondary to lower plasma angiotensin-converting enzyme activity or endothelin-1: nitric oxide. Nutr Res. 2012;32(8):557-64. PubMed
ORGANIC ANION TRANSPORTER 3 (OAT3) SUBSTRATES
2 of 4Hydrochlorothiazide, Pindolol also falls under ORGANIC ANION TRANSPORTER 3 (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.
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.
Your blood pressure pill combines hydrochlorothiazide (a water pill) with pindolol (a beta-blocker). The hydrochlorothiazide part relies on a kidney transporter called OAT3 to get shuttled into your urine. In test-tube studies, quercetin blocks that transporter pretty strongly. In theory, that could slow how fast the water pill leaves your body, so a bit more might hang around than expected.
If that happened, you might notice more of the usual hydrochlorothiazide effects, like extra urination, dizziness, low potassium, or feeling lightheaded when you stand. Here's the honest part: this is only lab data and has never been reported in actual people. Food amounts of quercetin are very unlikely to matter. Before starting a high-dose supplement, just run it by your pharmacist or doctor.
- 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
3 of 4Hydrochlorothiazide, Pindolol 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.
Viskazide combines two blood pressure medicines: hydrochlorothiazide (a water pill) and pindolol (a beta-blocker). The hydrochlorothiazide part is the piece that matters here. Your kidneys use a tiny transporter called OAT1 to push this water pill out into your urine. In lab dish studies, quercetin appears to block that transporter, which could theoretically slow how fast hydrochlorothiazide leaves your body and let it build up a bit.
If that happened, you might notice more of the drug's usual effects, like extra urination, dizziness, dehydration, or low potassium. The important thing: this has only been seen in test tubes, never reported in real people, so it's a theoretical concern. Food amounts of quercetin are very unlikely to matter, but check with your pharmacist before starting high-dose supplements.
- 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
4 of 4Hydrochlorothiazide, Pindolol 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.
Your Viskazide combines two medicines: hydrochlorothiazide (a water pill) and pindolol (a beta-blocker). The piece that matters here is pindolol, which the body partly clears using a liver enzyme called CYP2D6. In test-tube studies, quercetin appears to slow that enzyme down. If that happened in a real person, pindolol could build up a bit and push its effects too far.
What that might feel like is a slower heart rate, more tiredness, lightheadedness, or lower blood pressure than usual. Here is the reassuring part: this has only been seen in lab studies, never confirmed in people, so the concern is largely theoretical. Food amounts of quercetin are very unlikely to 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
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 Hydrochlorothiazide, Pindolol 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 Hydrochlorothiazide, Pindolol
This page covers Quercetin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Pindolol page lists 276 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Dolomite (major).
By severity: 11 major · 234 moderate · 31 minor.
From our pharmacist’s overview on the Hydrochlorothiazide, Pindolol page
“Viskazide is a two-in-one blood pressure treatment, hydrochlorothiazide (a water pill) plus pindolol (a beta blocker), which means supplements that touch blood pressure, fluid balance, or potassium can hit it from both directions. This combination deserves genuine caution, since 11 of the 276 interactions on file are rated major, and m…”
Reviewed by 2 · Jul 18, 2026
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 Hydrochlorothiazide, Pindolol 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 Hydrochlorothiazide, Pindolol 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.
#44 of 1,452 supplements looked up here in the last 7 days
#1,384 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 ›
- Acetaminophen ›
- Rosuvastatin ›
- Escitalopram ›
- Docusate ›
- Hydroxyurea ›
- Sumatriptan ›
- Amoxicillin ›
- Bendamustine ›
- Bupropion ›
- Azithromycin ›
- Pregabalin ›
- Lamotrigine ›
- Gabapentin ›
- Levothyroxine, Liothyronine ›
- Methylene Blue ›
- Amoxicillin, Clavulanate Potassium ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Cyclopentolate ›
- Ezetimibe ›
- Roxithromycin ›
- Levetiracetam ›
- Carbidopa, Levodopa ›
- Phentermine, Topiramate ›
- Dexmethylphenidate ›
- Levodopa ›
- Thyroid Hormone ›
- Levothyroxine Sodium ›
- Pizotifen ›
- Daptomycin ›
- Hexobarbitone ›
- Lenvatinib ›
- Mitomycin ›
- Pegunigalsidase Alfa-iwxj ›
- Flutemetamol F-18 ›
- Magnesium Hydroxide (otc Drug) ›
- Bentoquatam ›
- Salbutamol Sulfate ›
- Hethylphenidate Hcl ›
- Alglucosidase Alpha ›
- Factor 7a ›
- Amobarbital, Ephedrine Sulfate ›
- Acetaminophen, Brompheniramine, Phenylpropanolamine ›
- Vancomycin ›
- Tocainide ›
- Phenylephrine ›
- Paracetamol ›
- Azelaic Acid ›
- Bleomycin ›
- Ribavirin Aerosol ›
- Gestodene ›
- Hydroxychloroquine ›
- Birth Control Pills ›
- Ropinirole ›
- Alginic Acid, Aluminum Hydroxide ›
- Casanthranol, Docusate ›
- Lorazepam ›
- Rocuronium ›
- 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
Hydrochlorothiazide, Pindolol Is Linked to Lower Levels of 8 Nutrients
Natural Medicines records Hydrochlorothiazide, Pindolol 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 Hydrochlorothiazide, Pindolol 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 Hydrochlorothiazide, Pindolol Together: Common Questions
Can you take Quercetin with Hydrochlorothiazide, Pindolol?
Why are there 4 interactions listed for Quercetin and Hydrochlorothiazide, Pindolol?
How serious is the Quercetin and Hydrochlorothiazide, Pindolol interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Still Have a Question About Hydrochlorothiazide, Pindolol 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.