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Quercetin
•Last Updated: April 22, 2025
Quercetin is a flavonoid commonly found in many fruits and vegetables. There is some research that supports its use for reducing inflammation.
Quercetin is most often used for
Last Updated:April 22, 2025
Quercetin is a flavonoid that is naturally found in fruits and vegetables. It can be found in red wine, onions, apples, and berries, and the richest sources are wine and onions. It is also commonly taken as a supplement. Beyond fruits and vegetables, it is also found in the plants of other herbal supplements such as Ginkgo biloba, elderberry, and St. John’s wort.[7]
Some research suggests that quercetin may help improve systolic blood pressure and fasting blood glucose.[5] Some studies suggest that it may reduce inflammation by reducing C-reactive protein levels[3] and may reduce allergy symptoms,[6] but the research is still preliminary and not strong enough to draw any definitive conclusions about its benefits.
Quercetin works in multiple ways. It can be an antioxidant, which can help neutralize free radicals in the body. It may also modulate a few biological pathways that may regulate cell death, inflammation, and cellular growth signals.[8] It’s important to note that while these mechanisms are intriguing, its effects in isolation may not always apply to humans.
Note that Quercetin is also known as:
- 3,3',4'5,7-Pentahydroxyflavone
Quercetin should not be confused with:
- Quercitrin
- Quinines (a class of medications)
- Quinolones (a class of medications)
- Quercitannic acid
- Quercitron
- Sophoretin
- Flavin meletin
- Quercetol
Formulation:
Quercetin comes as a liquid or in capsules, tablets, or softgels. Most supplements use the aglycone (free form) version, which is considered less bioavailable than the quercetin glucosides found in foods.[1]
Range of dosages studied:
30 mg to 3 grams
Effective Dosages:
Inflammation
Adults (≤45 years): 500 mg/day or higher for 6 to 10 weeks to reduce C-reactive protein levels.[2][3]
Special considerations: Appears to be most effective in adults younger than 45 years, but there’s less evidence of effectiveness in adults older than 45 years. It’s important to note that it does not appear to affect other inflammatory markers, like IL-6 and TNF-alpha.
Blood pressure
Adults (19–60 years): More than 500 mg/day for more than 8 weeks may reduce systolic and diastolic blood pressure.[4][5]
Special considerations: The reductions in diastolic blood pressure are less consistent. The studies showed heterogeneity, which suggests that the actual blood pressure effect may vary from person to person.
General cardiovascular health
Adults (19–60 years): 100 to 500 mg/day for 8 to 12 weeks may help improve total cholesterol and LDL-C. Higher doses of more than 500 mg/day may further enhance LDL-C reduction.[5][2]
Special considerations: The studies showed heterogeneity, which suggests that the actual effect on blood lipids may vary from person to person
Allergic rhinitis (seasonal allergies/hay fever)
Adults (19–60 years): 200 mg/day[6]
Special considerations: This dosage recommendation is based on only one study, so the certainty of this recommendation is low.
Other considerations:
Because there is a limited amount of research, it’s unclear whether quercetin’s bioavailability is affected by food. More research is needed to determine how food affects the absorption and metabolism of quercetin.
Research FeedRead all studies
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- ^Dabeek WM, Marra MVDietary Quercetin and Kaempferol: Bioavailability and Potential Cardiovascular-Related Bioactivity in Humans.Nutrients.(2019 Sep 25)
- ^Reza Tabrizi, Omid Reza Tamtaji, Naghmeh Mirhosseini, Kamran B Lankarani, Maryam Akbari, Seyed Taghi Heydari, Ehsan Dadgostar, Zatollah AsemiThe effects of quercetin supplementation on lipid profiles and inflammatory markers among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trialsCrit Rev Food Sci Nutr.(2020)
- ^Mohammadi-Sartang M, Mazloom Z, Sherafatmanesh S, Ghorbani M, Firoozi DEffects of supplementation with quercetin on plasma C-reactive protein concentrations: a systematic review and meta-analysis of randomized controlled trials.Eur J Clin Nutr.(2017 Sep)
- ^Serban MC, Sahebkar A, Zanchetti A, Mikhailidis DP, Howard G, Antal D, Andrica F, Ahmed A, Aronow WS, Muntner P, Lip GY, Graham I, Wong N, Rysz J, Banach M, Lipid and Blood Pressure Meta‐analysis Collaboration (LBPMC) GroupEffects of Quercetin on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.J Am Heart Assoc.(2016 Jul 12)
- ^Noshadi, I. et alThe effect of quercetin supplementation on the components of metabolic syndrome in adults: A systematic review and dose–response meta-analysis of randomized controlled trialsJournal of Functional Foods.(2024-05-01)
- ^S Yamada, M Shirai, Y Inaba, T TakaraEffects of repeated oral intake of a quercetin-containing supplement on allergic reaction: a randomized, placebo-controlled, double-blind parallel-group studyEur Rev Med Pharmacol Sci.(2022 Jun)
- ^Devi V, Deswal G, Dass R, Chopra B, Kriplani P, Grewal AS, Guarve K, Dhingra AKTherapeutic Potential and Clinical Effectiveness of Quercetin: A Dietary Supplement.Recent Adv Food Nutr Agric.(2024)
- ^Li Y, Yao J, Han C, Yang J, Chaudhry MT, Wang S, Liu H, Yin YQuercetin, Inflammation and Immunity.Nutrients.(2016-Mar-15)
- ^Egert S, Bosy-Westphal A, Seiberl J, Kürbitz C, Settler U, Plachta-Danielzik S, Wagner AE, Frank J, Schrezenmeir J, Rimbach G, Wolffram S, Müller MJQuercetin reduces systolic blood pressure and plasma oxidised low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study.Br J Nutr.(2009 Oct)
- ^Ferry DR, Smith A, Malkhandi J, Fyfe DW, deTakats PG, Anderson D, Baker J, Kerr DJPhase I clinical trial of the flavonoid quercetin: pharmacokinetics and evidence for in vivo tyrosine kinase inhibition.Clin Cancer Res.(1996 Apr)
- ^Andres S, Pevny S, Ziegenhagen R, Bakhiya N, Schäfer B, Hirsch-Ernst KI, Lampen ASafety Aspects of the Use of Quercetin as a Dietary Supplement.Mol Nutr Food Res.(2018-Jan)
- ^Shoskes DA, Zeitlin SI, Shahed A, Rajfer JQuercetin in men with category III chronic prostatitis: a preliminary prospective, double-blind, placebo-controlled trial.Urology.(1999 Dec)
- ^Bedada SK, Neerati PEvaluation of the effect of quercetin treatment on CYP2C9 enzyme activity of diclofenac in healthy human volunteers.Phytother Res.(2018 Feb)
- ^Obach RSInhibition 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 Jul)
- ^Zhao Q, Wei J, Zhang HEffects of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats.Xenobiotica.(2019 May)
- ^Bhutani P, Rajanna PK, Paul ATImpact of quercetin on pharmacokinetics of quetiapine: insights from in-vivo studies in wistar rats.Xenobiotica.(2020 Dec)
- ^Choi JS, Choi BC, Choi KEEffect of quercetin on the pharmacokinetics of oral cyclosporine.Am J Health Syst Pharm.(2004 Nov 15)
- ^Choi JS, Jo BW, Kim YCEnhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin.Eur J Pharm Biopharm.(2004 Mar)
- ^DiCenzo R, Frerichs V, Larppanichpoonphol P, Predko L, Chen A, Reichman R, Morris MEffect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults.Pharmacotherapy.(2006 Sep)
- ^Elbarbry F, Ung A, Abdelkawy KStudying the Inhibitory Effect of Quercetin and Thymoquinone on Human Cytochrome P450 Enzyme Activities.Pharmacogn Mag.(2018 Jan)
- ^Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJEffect of quercetin on CYP3A activity in Chinese healthy participants.J Clin Pharmacol.(2012 Jun)
- ^Nguyen MA, Staubach P, Wolffram S, Langguth PThe Influence of Single-Dose and Short-Term Administration of Quercetin on the Pharmacokinetics of Midazolam in Humans.J Pharm Sci.(2015 Sep)
- ^Bedada SK, Neerati PThe effect of quercetin on the pharmacokinetics of chlorzoxazone, a CYP2E1 substrate, in healthy subjects.Eur J Clin Pharmacol.(2018 Jan)
- ^Chen Y, Xiao P, Ou-Yang DS, Fan L, Guo D, Wang YN, Han Y, Tu JH, Zhou G, Huang YF, Zhou HHSimultaneous action of the flavonoid quercetin on cytochrome P450 (CYP) 1A2, CYP2A6, N-acetyltransferase and xanthine oxidase activity in healthy volunteers.Clin Exp Pharmacol Physiol.(2009 Aug)
- ^Kim KA, Park PW, Park JYShort-term effect of quercetin on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein, in healthy volunteers.Eur J Clin Pharmacol.(2009 Jun)
- ^Nguyen MA, Staubach P, Wolffram S, Langguth PEffect of single-dose and short-term administration of quercetin on the pharmacokinetics of talinolol in humans - Implications for the evaluation of transporter-mediated flavonoid-drug interactions.Eur J Pharm Sci.(2014 Sep 30)
- ^S-Y Wang, K-M Duan, Y Li, Y Mei, H Sheng, H Liu, X Mei, W Ouyang, H-H Zhou, Z-Q LiuEffect of quercetin on P-glycoprotein transport ability in Chinese healthy subjectsEur J Clin Nutr.(2013 Apr)
- ^Wu LX, Guo CX, Chen WQ, Yu J, Qu Q, Chen Y, Tan ZR, Wang G, Fan L, Li Q, Zhang W, Zhou HHInhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment.Br J Clin Pharmacol.(2012 May)
- ^Ni Y, Duan Z, Zhou D, Liu S, Wan H, Gui C, Zhang HIdentification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids.Front Pharmacol.(2020)
- ^Song YK, Yoon JH, Woo JK, Kang JH, Lee KR, Oh SH, Chung SJ, Maeng HJQuercetin Is a Flavonoid Breast Cancer Resistance Protein Inhibitor with an Impact on the Oral Pharmacokinetics of Sulfasalazine in Rats.Pharmaceutics.(2020 Apr 26)
- ^Ahmad E, Jahangir M, Bukhari NI, Khan J, Sarwar A, Aziz T, Nabi G, Alharbi M, Thamer HA, Alasmari AFInfluence of quercetin on amiodarone pharmacokinetics and biodistribution in rats.Eur Rev Med Pharmacol Sci.(2023 Dec)
- ^Di Bari L, Ripoli S, Pradhan S, Salvadori PInteractions between quercetin and warfarin for albumin binding: A new eye on food/drug interference.Chirality.(2010 Jun)
- ^Ahmad E, Jahangir M, Ismail MA, Afzal H, Bano S, Shamim R, Bukhari NIInfluence of Quercetin Pretreatment on Pharmacokinetics of Warfarin in Rats.Curr Drug Saf.(2023)
- ^Vida RG, Fittler A, Somogyi-Végh A, Poór MDietary quercetin supplements: Assessment of online product informations and quantitation of quercetin in the products by high-performance liquid chromatography.Phytother Res.(2019 Jul)
- ^Romaszko E, Wiczkowski W, Romaszko J, Honke J, Piskula MKExposure of breastfed infants to quercetin after consumption of a single meal rich in quercetin by their mothers.Mol Nutr Food Res.(2014 Feb)
- Oxidative Stress Biomarkers - Boots AW, Drent M, de Boer VC, Bast A, Haenen GRQuercetin reduces markers of oxidative stress and inflammation in sarcoidosisClin Nutr.(2011 Aug)
- Oxidative Stress Biomarkers - Randi L. Edwards, Tiffany Lyon, Sheldon E. Litwin, Alexander Rabovsky, J. David Symons, and Thunder JaliliQuercetin Reduces Blood Pressure in Hypertensive SubjectsAmerican Society for Nutrition.()
- Blood Pressure - Egert S, Rimbach G, Müller MJNo evidence for a thermic effect of the dietary flavonol quercetin: a pilot study in healthy normal-weight womenEur J Appl Physiol.(2011 May)
- Rating of Perceived Exertion - Cheuvront SN, Ely BR, Kenefick RW, Michniak-Kohn BB, Rood JC, Sawka MNNo effect of nutritional adenosine receptor antagonists on exercise performance in the heatAm J Physiol Regul Integr Comp Physiol.(2009 Feb)
- Exercise-induced Stress Response - Kuennen M, Gillum T, Dokladny K, Bedrick E, Schneider S, Moseley PThermotolerance and heat acclimation may share a common mechanism in humansAm J Physiol Regul Integr Comp Physiol.(2011 Aug)
- Anaerobic Capacity - Abbey EL, Rankin JWEffect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammationInt J Sport Nutr Exerc Metab.(2011 Apr)
- High-density lipoprotein (HDL) - Talirevic E, Jelena SQuercetin in the treatment of dyslipidemiaMed Arh.(2012)
- Sleep Quality - Bigelman KA, Chapman DP, Freese EC, Trilk JL, Cureton KJEffects of 6 weeks of quercetin supplementation on energy, fatigue, and sleep in ROTC cadetsMil Med.(2011 May)
- Quality of Life - Mantadaki AE, Linardakis M, Vafeiadi M, Anastasiou F, Tsatsakis A, Symvoulakis EKThe Impact of Three-Month Quercetin Intake on Quality of Life and Anxiety in Patients With Type II Diabetes Mellitus: An Early Data Analysis From a Randomized Controlled Trial.Cureus.(2024 Apr)
- HbA1c - Mantadaki AE, Linardakis M, Tsakiri M, Baliou S, Fragkiadaki P, Vakonaki E, Tzatzarakis MN, Tsatsakis A, Symvoulakis EKBenefits of Quercetin on Glycated Hemoglobin, Blood Pressure, PiKo-6 Readings, Night-Time Sleep, Anxiety, and Quality of Life in Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial.J Clin Med.(2024 Jun 15)