Quercetin: What It Does for Blood Pressure, Uric Acid, and Endurance

A plant pigment found in onions and apples is one of the more evidence-backed polyphenols for heart health and exercise performance.

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By the Ration Editorial Team · Reviewed against primary research · Updated July 14, 2026

Quercetin is a flavonoid, a type of polyphenol that gives many fruits and vegetables their color.

It is found naturally in onions, apples, berries, capers, and tea.

It is also sold as a standalone capsule supplement, often paired with vitamin C or bromelain to improve absorption.

Like many polyphenols, quercetin is studied for its antioxidant and anti-inflammatory properties, though its effects in the body are more nuanced than 'antioxidant' alone suggests^[5].

Quercetin interacts with several enzymes and signaling pathways rather than acting through one single mechanism.

• It inhibits xanthine oxidase, an enzyme that produces uric acid from purines^[7][9]
• It may activate AMPK, a cellular energy sensor tied to mitochondrial biogenesis^[11]
• It has vasodilating properties that may help relax blood vessels and ease blood pressure^[12]
• It can modulate gut bacteria involved in producing uremic toxins^[3]

These actions overlap with pathways affected by related compounds like rutin and luteolin, which are structurally similar flavonoids^[9].

This is one of the better-supported effects of quercetin.

A 2022 meta-analysis of randomized trials found quercetin supplementation modestly reduced systolic blood pressure, with larger effects seen at doses above 500 mg per day^[6].

An earlier systematic review and meta-analysis reported similar findings, alongside small improvements in some lipid markers^[10].

Mechanistic work suggests quercetin may support endothelial function and nitric oxide availability, which could explain the blood pressure effect^[12].

The overall evidence grade here is strong, based on six sources pointing in the same direction.

• ↓Systolic Blood PressureAHuman trials

  Research may lower Systolic Blood Pressure · strong agreement · 6 studies

  View 5 studies on PubMed

  • The Effects of Quercetin Supplementation on Blood Pressure - Meta-Analysis (2022)
  • Effect of quercetin supplementation on plasma lipid profiles, blood pressure, and glucose levels: a systematic review and meta-analysis (2020)
  • Effects of Quercetin on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (2016)
  • Quercetin and metabolic syndrome: A review (2021)
  • Actions of Quercetin, a Polyphenol, on Blood Pressure (2017)
• ↓Uric AcidAHuman trials

  Research may lower Uric Acid · strong agreement · 6 studies

  View 5 studies on PubMed

  • Quercetin lowers plasma uric acid in pre-hyperuricaemic males: a randomised, double-blinded, placebo-controlled, cross-over trial (2016)
  • Quercetin decreases fructose drinking in model of fructose-induced insulin resistance. Unexpected uric acid and TBARS lowering effect of methyl cellulose vehicle and fructose combination (2024)
  • Effects of quercetin and metabolites on uric acid biosynthesis and consequences for gene expression in the endothelium (2021)
  • Quercetin ameliorates hyperuricemic nephropathy through improving gut dysfunctions and decreasing gut bacteria-derived uremic toxins (2025)
  • The Uric Acid Degrading Probiotics MC1 in Quercetin Nanocoatings and Bioactive Polysaccharides Microgels for Anti-Hyperuricemia and Gut Microenvironment Modulation (2026)
• ↑VO2maxAHuman trials

  Research may raise VO2max · strong agreement · 6 studies

  View 5 studies on PubMed

  • Quercetin and endurance exercise capacity: a systematic review and meta-analysis (2011)
  • Effects of quercetin supplementation on endurance performance and maximal oxygen consumption: a meta-analysis (2013)
  • Effects of propolis intake on endurance exercise and molecular signaling related to inflammation and oxidative stress (2025)
  • Mitochondrial biogenesis: pharmacological approaches (2014)
  • Effect of Quercetin Treatment on Mitochondrial Biogenesis and Exercise-Induced AMP-Activated Protein Kinase Activation in Rat Skeletal Muscle (2020)

Across the graded effects, quercetin has consistent, grade A evidence for lowering systolic blood pressure and uric acid, and for increasing VO2max.

For uric acid, human and animal studies show quercetin reduces levels by inhibiting xanthine oxidase and by modulating gut bacteria linked to uremic toxin production^{[1][3][4][7][9]}.

One 2026 study combined quercetin with a uric acid degrading probiotic in a nanocoating delivery system, reporting improvements in both uric acid and gut microbial balance, though this is early-stage work^[1].

For VO2max, a rat study found quercetin activated AMPK and supported mitochondrial biogenesis in skeletal muscle, a plausible mechanism for endurance gains^[11].

A related human trial on propolis, which contains quercetin among other compounds, found benefits for markers of inflammation and oxidative stress during endurance exercise^[2].

High uric acid is central to gout and is linked to metabolic syndrome^[8].

Cultured hepatocyte studies show quercetin, along with related compounds like rutin, apigenin, and luteolin, can suppress uric acid production directly in liver cells^[9].

In a fructose-driven insulin resistance model, quercetin lowered uric acid and reduced markers of oxidative stress, though the study noted the vehicle itself, methyl cellulose, had unexpected effects that complicate interpretation^[4].

A 2025 study found quercetin improved gut function and reduced uremic toxins in a model of hyperuricemic kidney damage^[3].

These findings are promising but come mostly from animal and cell studies, so human trial data specifically on gout outcomes remains limited.

Most clinical trials use doses between 500 mg and 1,000 mg per day, typically for several weeks.

The blood pressure meta-analysis found stronger effects at doses above 500 mg daily, suggesting a possible dose threshold^[6].

Dietary intake from foods like onions and apples is much lower than supplemental doses used in trials, often just tens of milligrams per day.

• Onions, especially red onions
• Apples, particularly with the skin
• Berries such as cranberries and blueberries
• Capers
• Black and green tea
• Kale and other leafy greens

Quercetin is generally well tolerated in the doses used in research.

Mild side effects reported in trials include headache and stomach upset.

Long-term safety data at high supplemental doses is still limited, and quercetin may interact with certain medications metabolized by the liver.

As with any supplement, this article is not medical advice, and anyone considering quercetin, especially alongside medications for blood pressure or gout, should discuss it with a healthcare provider.

• People interested in modest, adjunctive support for blood pressure already under medical management^[6][10]
• Those researching natural approaches to uric acid management alongside standard care^[1][7][9]
• Endurance athletes curious about mitochondrial and VO2max support^[11][2]
• People who already eat a polyphenol-rich diet and want to understand the underlying compounds^[5]

Quercetin has some of the more consistent human trial evidence among popular polyphenol supplements, particularly for blood pressure^[6][10][12].

Its uric acid lowering effects are backed by a growing body of animal and mechanistic research, with human data still developing^{[1][3][4][7][9]}.

The VO2max findings are encouraging but rest on a smaller, more mixed evidence base^[11][2].

Getting quercetin through onions, apples, and tea remains a reasonable baseline, with supplements reserved for those pursuing the specific doses studied in trials.

58 foods with measured values · compiled from published research · updated as the literature grows