Supplement
Flavonoid with antioxidant and endothelial support potential.[1973,2463,2706, etc.]
Superscript reference numbers link to the Sources bibliography.
Composite Rating
Blends evidence depth, community direction, safety friction, and completeness.
Evidence Intensity
100/100
High depth from human/RCT/meta counts
Community Direction
18
Positive Lean • confidence Minimal
Safety Friction
100/100
High signal from adverse/interaction markers
Data Completeness
100%
Studies 15 • mentions 4 • links 25
Not medical advice. This product is for educational and informational purposes only. It does not diagnose, treat, cure, or prevent any disease and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
FDA disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Results may vary. Not intended for use by pregnant or nursing women, individuals under 18, or those with known medical conditions without physician consultation.
If you are experiencing a medical emergency, call 911 or your local emergency number immediately.
Goal alignment: Immune Support, Heart Health, Longevity.[614,758,988, etc.]
Dose guide: Human-study daily dose: 200 mg-1000 mg/day (higher-confidence extraction from PubMed abstracts)..[614,758,988, etc.]
Category
Botanical
Evidence Tier
HIGH
Daily Guide
Human-study daily dose: 200 mg-1000 mg/day (higher-confidence extraction from PubMed abstracts).
Clinical Depth
Humans: 1,229 • RCTs: 156 • Meta: 30
Cohort / Real-World
Cohort signals: 0
Safety Markers
Adverse signals: 3,005 • Interactions: 4,090
Freshness, trend, and study timeline for this item
Status
Trend
→ Stable evidence base
Depth
3029 total studies · 4 recent
Timeline
Animal-only studies
8,339
In vitro / tissue
8,084
Interaction signals
4,090
Total indexed
3,029
Safety adverse signals
3,005
Human studies
1,229
Weighted direction score: 18 (Positive Lean)
High when >=2 human meta-analyses, or >=5 human RCTs with substantial human literature volume.
Animal-only studies
8,339
In vitro / tissue
8,084
Interaction signals
4,090
Total indexed
3,029
Safety adverse signals
3,005
Human studies
1,229
Randomized trials
156
Meta-analyses
30
Distribution of evidence by study design strength
Evidence Strength: High
Composite of study volume, RCTs, and meta-analyses
PMID 40037045 • 2025 Jun 15
Improving quercetin bioavailability: A systematic review and meta-analysis of human intervention studies.
Food Chem
Open PubMedPMID 29518971 • 2018 Mar 7
Dietary Plants for the Prevention and Management of Kidney Stones: Preclinical and Clinical Evidence and Molecular Mechanisms.
Int J Mol Sci
Open PubMedPMID 28097488 • 2017 Aug
Polyphenols and Performance: A Systematic Review and Meta-Analysis.
Sports Med
Open PubMedPMID 40771814 • 2025
Efficacy and safety of dietary polyphenol supplements for COPD: a systematic review and meta-analysis.
Front Immunol
Open PubMedPMID 35948195 • 2022 Nov
The Effects of Quercetin Supplementation on Blood Pressure - Meta-Analysis.
Curr Probl Cardiol
Open PubMedPMID 25897620 • 2017 Mar 4
Effects of quercetin supplementation on lipid profile: A systematic review and meta-analysis of randomized controlled trials.
Crit Rev Food Sci Nutr
Open PubMedPMID 35776034 • 2022 Jun
Effects of repeated oral intake of a quercetin-containing supplement on allergic reaction: a randomized, placebo-controlled, double-blind parallel-group study.
Eur Rev Med Pharmacol Sci
Open PubMedPMID 39417670 • 2024 Dec
The effect of quercetin and citrulline on cycling time trial performance.
J Int Soc Sports Nutr
Open PubMedPMID 27794196 • 2017 Mar
Short-term biomarkers of apple consumption.
Mol Nutr Food Res
Open PubMedPMID 37344086 • 2023 Aug
Effects of quercetin supplementation on endothelial dysfunction biomarkers and depression in post-myocardial infarction patients: A double-blind, placebo-controlled, randomized clinical trial.
Clin Nutr ESPEN
Open PubMedPMID 40162673 • 2025 Jul
Adding collagen, propolis plus quercetin, bacillus coagulans, hyaluronic acid and chondroitin sulphate to D-mannose avoids symptoms and prevents recurrence in women with recurrent urinary tract infections: a single-blind randomized controlled trial.
Expert Rev Anti Infect Ther
Open PubMedPMID 20478383 • 2010 Sep
Quercetin supplementation and upper respiratory tract infection: A randomized community clinical trial.
Pharmacol Res
Open PubMedPMID 35315418 • 2022 Mar 14
Dietary supplements for treatment of endometriosis: A review.
Acta Biomed
Open PubMedPMID 36480969 • 2022 Dec 13
Micronutrient Supplementation to Reduce Cardiovascular Risk.
J Am Coll Cardiol
Open PubMedPMID 29127724 • 2018 Jan
Safety Aspects of the Use of Quercetin as a Dietary Supplement.
Mol Nutr Food Res
Open PubMedBenefit reports: 2
Adverse reports: 1
No-effect reports: 0
Mixed reports: 1
Unclear reports: 0
Signal confidence: 0.00
Benefits
Adverse
No Effect
Often paired with bromelain in user stacks. | Step2: Insufficient empirical signal for a directional adjustment.
Reddit evidence: 0 mentions (confidence 0.00).
Amazon signal: 0 products scanned (confidence 0.00).
GNC signal: 0 products scanned (confidence 0.00) [BLOCKED].
PerimeterX / captcha block encountered.
Search fetch failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=relevance&t=year&limit=12&q=%22quercetin%22%20(supplement%20OR%20dosage%20OR%20stack%20OR%20side%20effects%20OR%20review)%20(subreddit%3ASupplements%20OR%20subreddit%3ANootropics%20OR%20subreddit%3ABiohackers%20OR%20subreddit%3Alongevity%20OR%20subreddit%3ANutrition%20OR%20subreddit%3AHubermanLab%20OR%20subreddit%3ASleep%20OR%20subreddit%3AFitness%20OR%20subreddit%3Aketoscience%20OR%20subreddit%3AStackAdvice)
Fallback search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=comments&t=all&limit=16&q=%22quercetin%22%20(supplement%20OR%20capsule%20OR%20powder%20OR%20experience%20OR%20results%20OR%20side%20effects)
Broad search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=new&t=all&limit=16&q=quercetin
Use adverse/interactions PubMed signal counts for screening; perform clinician review before high-dose or multi-drug stack use.
Human-study daily dose signal: 200 mg-1000 mg/day (confidence HIGH).
Extracted from 4 dosing mentions across 3 PubMed studies (mg/day).
Imported legacy community score: 8.0/10 (heuristic mapping confidence 1.00).
Imported legacy monthly cost signal: ~$18.00.
Legacy community note: Massive popularity surge due to senolytic research and COVID-era zinc ionophore interest. Users report reduced allergy symptoms, less inflammation, and improved recovery. Phytosome form widely recommended for bioavailability.
aggregate • benefit
Aggregate community signal: 4 directional mentions (benefit 2, adverse 1, no-effect 0, mixed 1).
Open mentionamazon
Amazon search for Quercetin
Rating: n/a | Reviews: n/a
Open productEvidence Sources
Community Sources
RCT • 2021 • Adults
Moderate-size human trials.
Outcome: Small improvements in blood pressure in some cohorts.[1973,2463,2706, etc.]
PUBMED • Humans + preclinical triage
Counts aggregated from automated literature sweep and tiering rules.
Outcome: Tier HIGH; humans 1229, RCTs 156, meta-analyses 30.[1973,2463,2706, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40037045 from Food Chem.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2018 • Human evidence curation set
PMID 29518971 from Int J Mol Sci.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2017 • Human evidence curation set
PMID 28097488 from Sports Med.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40771814 from Front Immunol.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 35948195 from Curr Probl Cardiol.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2017 • Human evidence curation set
PMID 25897620 from Crit Rev Food Sci Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 35776034 from Eur Rev Med Pharmacol Sci.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 39417670 from J Int Soc Sports Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2017 • Human evidence curation set
PMID 27794196 from Mol Nutr Food Res.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37344086 from Clin Nutr ESPEN.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 40162673 from Expert Rev Anti Infect Ther.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2010 • Human evidence curation set
PMID 20478383 from Pharmacol Res.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 35315418 from Acta Biomed.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 36480969 from J Am Coll Cardiol.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open sourcePUBMED • 2018 • Human evidence curation set
PMID 29127724 from Mol Nutr Food Res.
Outcome: See linked PubMed abstract for methods and outcomes.[1973,2463,2706, etc.]
Open source