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Compound Profile
Quercetin
Quercetin carries a Grade B rating — moderate evidence.
Last reviewed: •5 sources citedReport a correctionProfile-wide ·B Moderate
Review needed — Headache, tingling Details
- Evidence
- Moderate evidence
- Typical onset
- Varies by prep
- Safety rating
- Review needed: Safety review pending
- Best for
- Antioxidant, Anti Inflammatory, Antihistamine
- Avoid / review if
- Antibiotics (Quinolones), Anticoagulants
Safety
Safety & Cautions
Headache, tingling
Standard caution
Caution level: Standard. No specific caution categories were detected in the source record.
Evidence-based safety
Caution when combined
Severity and certainty are shown separately. A high-priority caution can still be theoretical: these pairings are screened from shared contraindication mechanisms and are not automatically documented clinical interactions. Provenance identifies the source fields that produced each flag; it does not upgrade the certainty of the pairwise claim.
High-Priority Caution
147 flagged pairingsBleeding / anticoagulant risk
High-Priority Caution
147 flagged pairingsBleeding / anticoagulant risk
Representative pairings are shown below. Large mechanism groups are intentionally summarized to keep profiles focused and crawl-efficient.
Bleeding / anticoagulant riskCertainty: Theoretical
Data provenance recorded for 147 of 147 pairings in this mechanism group.
- aescin — Theoretical interaction certainty
- Aged Garlic Extract — Theoretical interaction certainty
- ajoene — Theoretical interaction certainty
- Ajwain — Theoretical interaction certainty
- Allicin — Theoretical interaction certainty
- Garlic — Theoretical interaction certainty
- American Ginseng Extract — Theoretical interaction certainty
- Andrographis — Theoretical interaction certainty
- Angelica Archangelica — Theoretical interaction certainty
- Angelica Dahurica — Theoretical interaction certainty
- Angelica Pubescens — Theoretical interaction certainty
- Angelica Root — Theoretical interaction certainty
+135 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Evidence Summary
Profile-wide ·B ModerateEvidence lens
Useful signal, but study design, dose, and population still matter.
ModerateModerate evidence
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Inflammatory Signaling Modulation · Oxidative Stress Modulation · Metabolic Regulation
Research maturity: Established research — main contexts: Antioxidant · Anti Inflammatory · Antihistamine
Safety boundary: Safety note available — Headache, tingling
This profile cites 5 human studies.
Evidence Strength
Confidence estimate based on the design quality and consistency of published clinical trials.
Quercetin has a moderate evidence rating.
AdaptogenStress & MoodLongevity
Citation density
2.7
Sources
8
Effects
3
Research recency
Mixed recency
Evidence Grade
Grade B: Moderate Evidence
Evaluation of methodological rigor, population reach, and evidence alignment.
- Design Match
- Meta analysis
- Risk of Bias
- Low
- Consistency
- Consistent
Strongest recorded design is a meta analysis, drawn from 10 recorded studies, 10 in people. No disagreement is recorded across them.
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
Clinical Study Summaries (8)7 human evidence sources · 4 human trials · Participant totals not consistently reported · Consistency not yet classifiable
Filter by study class
Showing 8 of 8 studies.
What the evidence actually shows
This table contains 8 structured sources, including 7 human evidence sources; 4 are human trials.
| Study | Design | N | Dose | Duration | Population | Outcome | Result & magnitude | Source |
|---|---|---|---|---|---|---|---|---|
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A 2025 meta-analysis of seven randomized trials in MASLD reported improvements in several liver enzymes, lipid measures, and CRP with quercetin, while kidney function, BMI, body fat, hematologic markers, and TNF-alpha did not significantly improve. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A meta-analysis of nine randomized trials found no significant effect of quercetin on body weight, BMI, waist circumference, or waist-to-hip ratio. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | A meta-analysis of eight randomized trials found a small reduction in systolic blood pressure with quercetin, while diastolic blood pressure, VCAM-1, and ICAM-1 did not significantly change. | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | Acute mountain sickness occurred in 2% of quercetin participants versus 25% of placebo; quercetin participants also had higher SpO2 and several favorable physiologic/oxidative markers. | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | SRS improved within the quercetin group (p=0.010), but the between-group change was not statistically significant. | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | Quercetin and chlorhexidine both reduced Gingival Index versus placebo (p<0.001). | PubMed → |
Show 2 more studies
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | Effects of Quercetin Glycosides on Immune Responses to an mRNA Booster Vaccination in Older or Metabolically At-Risk Adults: A Randomized Double-Blind Placebo-Controlled Trial | PubMed → |
Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men | PubMed → |
How Quercetin Works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Quercetin Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Dosing
- Dose guidance
- 500 1000 mg/day
Mechanisms & biological pathways
Preclinical mechanism details from scientific profiles; these represent plausible pathways but do not guarantee clinical efficacy in humans.
- Inflammatory Signaling Modulation
- Oxidative Stress Modulation
- Metabolic Regulation
- Vascular Function Support
- Stress Response Modulation
- Endothelial Function
Botanical Context
Source botanicals and comparison guides related to Quercetin.
Found in
Compare active botanicals
Compare & Sourcing
Compare side-by-side tradeoffs or verify active marker guidelines.
Sourcing options
Quercetin product picks
Recommendation status
Product recommendations are not shown for this profile because the current site safety and monetization policy does not permit them.
Product form & quality guidelines
When sourcing Quercetin, verify the label for:
- Standardized Extract: Confirm active content percentages on the supplement facts panel (e.g. standardized to specific marker compounds) rather than simple raw herb weights.
- Third-Party Testing: Look for independent purity labels (USP, NSF, ConsumerLab, or Eurofins) to ensure the product is free from heavy metals, solvents, and contaminants.
- Form Bioavailability: Ensure the form matches evidence-supported configurations (e.g. chelated bisglycinate/glycinate for magnesium, micronized monohydrate for creatine) for optimal onset and digestion tolerance.
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Founder & Head Researcher · Oak Ridge, TN · Last reviewed August 2026
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
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