Records 221–260 of 290. Open a study to inspect the full evidence record. Source links lead directly to the publication. Updated 19 October 2026.
Forms, absorption and food sources (6) · Exercise and recovery (11) · Evidence reviews and human mechanisms (2) · Immunity and respiratory health (4) · Safety, interactions and special populations (7) · Brain, cognition and sleep (1) · Kidney and cancer research (2) · Skin and topical formulations (1) · Bone and joint health (1) · Allergies, histamine and mast cells (2) · Cardiovascular and metabolic health (3)
Human dietary flavonoid pharmacokinetic study. Quercetin had much lower urinary recovery than the other flavonoids despite comparable exposure to hesperetin.
Randomized double-blind placebo-controlled community exposure study. Fasting plasma quercetin rose substantially but variably; demographic and lifestyle measures did not explain the variation.
Comparative human glycoside absorption study. The modified glycoside produced greater exposure to quercetin metabolites than the comparator glycosides.
Human repeated-dose pharmacokinetic study with population modeling. Quercetin and conjugates showed re-entry concentration peaks consistent with enterohepatic recirculation; the modeled aglycone terminal half-life averaged 3.5 hours.
Randomized crossover food-matrix absorption study. The aglycone-rich dried skin preparation produced higher plasma exposure than the glucoside-rich flesh preparation.
Randomized dose-ranging human supplementation study. Plasma quercetin increased with dose, but measured antioxidant, inflammatory, lipid, body-composition, and metabolic outcomes did not improve.
Randomized double-blind placebo-controlled crossover exercise trial. Maximal oxygen uptake and cycling time to fatigue increased relative to placebo.
Randomized double-blind placebo-controlled military-training trial. Peak oxygen uptake, fitness-test results, sprinting, and anaerobic performance did not improve.
Randomized double-blind placebo-controlled ultramarathon trial. Perceived exertion and finishing times did not differ between groups.
Randomized double-blind placebo-controlled multi-arm exercise trial. The multi-ingredient arm improved selected immune and inflammatory measures; mitochondrial gene-expression outcomes did not differ between groups.
Randomized double-blind placebo-controlled exercise trial. Muscle oxidative capacity, oxygen uptake, cycling performance, fatigue, and perceived effort did not improve relative to placebo.
Randomized placebo-controlled exercise trial. Quercetin did not improve cycling efficiency, substrate use, perceived effort, or measured metabolic responses.
Randomized placebo-controlled exercise biomarker trial. Exercise increased oxidative and inflammatory markers, and quercetin did not attenuate those responses.
Double-blind placebo-controlled ultramarathon trial. Quercetin did not improve race performance or measured blood antioxidant capacity and oxidative damage.
Randomized double-blind placebo-controlled cyclist biomarker trial. Selected leukocyte cytokine-expression responses decreased, but muscle markers and most plasma cytokine responses did not differ.
Randomized double-blind placebo-controlled ultramarathon trial. Quercetin did not attenuate muscle-damage markers, cytokine responses, cortisol, or leukocyte cytokine-expression changes.
Randomized double-blind crossover cycling study. The quercetin-containing formulation improved cycling time relative to baseline.
Human gene-expression discovery study with placebo-controlled crossover verification. Initial microarray signals were poorly replicated; only small changes in a few targets distinguished quercetin from placebo.
Human supplementation study with murine cell experiments. Quercetin increased PON2 expression in cultured macrophages but not in circulating human monocytes after supplementation.
Randomized double-blind placebo-controlled community trial. There was no overall reduction in upper-respiratory illness outcomes. A fitter subgroup aged at least 40 showed lower symptom severity and sick days at 1,000 mg.
Randomized double-blind placebo-controlled immune-function analysis. Natural killer-cell activity, granulocyte function, leukocyte subsets, and measured cytokines did not improve.
Randomized double-blind placebo-controlled ultramarathon trial. Illness rates and exercise-related immune changes did not improve.
Randomized double-blind placebo-controlled exercise and illness trial. Reported upper-respiratory illness occurred in 1 of 20 quercetin recipients versus 9 of 20 placebo recipients; exercise-related immune-function changes did not differ.
Open-label within-subject steady-state pharmacokinetic study. Quercetin did not increase resveratrol exposure; a high-fat breakfast reduced it. Diarrhea was frequent during the high-dose resveratrol study.
Within-subject human enzyme-probe interaction study. Caffeine-metabolite ratios suggested lower CYP1A2 activity but higher activity of several other measured pathways.
Placebo-controlled human drug-interaction study. Fexofenadine exposure rose by approximately 55% and peak concentration by approximately 68% during quercetin treatment.
Uncontrolled acute niacin-flush pilot with laboratory support. Self-reported flushing intensity and duration were lower with the supplement formulation.
Critical narrative toxicology and safety review. The authors interpreted available in vivo evidence as supporting food-use safety despite some positive in vitro mutagenicity findings.
Double-blind randomized crossover dietary platelet pilot. The high-quercetin soup reduced selected collagen-stimulated platelet aggregation and signaling responses ex vivo.
Original sources: PubMed
Prospective human pharmacokinetic interaction study. Average plasma saquinavir exposure did not change substantially; intracellular concentrations were highly variable.
Double-blind placebo-controlled acute vigilance experiment. Caffeine improved vigilance and selected mood ratings; quercetin did not significantly change the measured outcomes.
Clinical perioperative antioxidant-combination report. The abstract reports changes in lipid-peroxidation and antioxidant measures and faster functional recovery.
Original sources: PubMed
Uncontrolled pilot case series. Polyp number and size decreased from baseline in all five participants.
Randomized active-comparator topical mouth-ulcer trial. Ulcer size and healing outcomes favored topical quercetin in the reported comparisons.
Original sources: PubMed
Uncontrolled joint-supplement intervention. Osteoarthritis symptoms and selected synovial-fluid measures improved; comparable changes were not seen in rheumatoid arthritis.
Randomized double-blind placebo-controlled allergy trial. Selected ocular symptoms improved; most nasal and cytokine measures did not show significant differences.
Double-blind placebo-controlled parallel-group allergy trial. Selected ocular symptom and medication scores improved; nasal symptoms and serum IgE did not differ significantly.
Randomized double-blind placebo-controlled crossover trial. Systolic pressure and oxidized LDL decreased modestly. HDL also decreased, while most lipid ratios and inflammatory markers were unchanged.
Randomized placebo-controlled crossover vascular biomarker study. Quercetin increased selected nitric-oxide-related measures and reduced endothelin-1; oxidative-stress markers did not improve.
Randomized double-blind placebo-controlled crossover trial. Blood pressure decreased in participants with stage 1 hypertension but not those with prehypertension; oxidative-stress measures did not improve.
Design tiers organize different kinds of evidence; read the source-specific limitations before applying a result. The full library is curated by Biohack Blueprint. Each evidence record lists its editorial author and reviewers.
