Tier 2 — strong

Effects of Quercetin and Citrulline on Nitric Oxide Metabolites and Antioxidant Biomarkers in Trained Cyclists

Jennifer A Kurtz, Rafaela G Feresin, Jacob Grazer, Jeff Otis, Kathryn E Wilson, J Andrew Doyle, Kevin A Zwetsloot
Nutrients 2025 17(2):224

Bibliography

PubMed
PMID 39861353
PubMed Central
PMC11767657
DOI
10.3390/nu17020224
Funding
Reported funding/support: This research received no external funding.
Competing interests
Reported disclosure: The authors declare no conflicts of interest.

Study snapshot

DesignRandomized double-blind placebo-controlled four-arm trial
ModelHuman intervention research
Sample50 trained cyclists: 42 men and 8 women
InterventionQuercetin, citrulline, their combination or placebo twice daily; amounts require full methods
Duration28 days
EndpointsOxidative-stress measures; Exposure and pharmacokinetics

What the study showed, in plain terms

Published in 2025, this source examined exercise and recovery. Design: Randomized double-blind placebo-controlled four-arm trial. Sample/model: 50 trained cyclists: 42 men and 8 women. The exposure or intervention was Quercetin, citrulline, their combination or placebo twice daily; amounts require full methods. Follow-up or treatment period: 28 days.

Group interactions for nitric-oxide metabolites and antioxidant measures were not significant. The combination did not demonstrate the expected biomarker advantage.

Companion biomarker analysis of a multi-arm exercise trial. Avoid counting related performance reports as independent replications.

Continue with Quercetin Data Center

For topic-level interpretation, read Quercetin for Exercise: Performance, Recovery and Muscle. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • Group interactions for nitric-oxide metabolites and antioxidant measures were not significant.
  • The combination did not demonstrate the expected biomarker advantage.
  • The recorded outcome domains were Oxidative-stress measures; Exposure and pharmacokinetics.
  • The result applies to the tested exposure: Quercetin, citrulline, their combination or placebo twice daily; amounts require full methods; 28 days.

What this study can and cannot tell us

  • Companion biomarker analysis of a multi-arm exercise trial. Avoid counting related performance reports as independent replications.
  • An individual controlled trial must be interpreted alongside its comparator, sample size, endpoint selection and independent replication. It does not validate a different commercial formulation or a general longevity claim.
  • Companion or correction records are linked below. They should not be counted automatically as independent replications; see the individual source notes for the relationship.
  • Source basis: Source check: accessible full text and indexed metadata. Missing method details, funding information or participant denominators are not inferred.

Related papers in the corpus

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The effect of quercetin and citrulline on cycling time trial performance
Jennifer A Kurtz et al. · Journal of the International Society of Sports Nutrition · 2024
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Quercetin prophylaxis in prevention of acute mountain sickness (AMS): a randomized, double blind, placebo controlled phase-II clinical trials
Sarada S K Sagi et al. · European journal of nutrition · 2026
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Quercetin ingestion alters motor unit behavior and enhances improvement in muscle strength following resistance training in older adults: a randomized, double-blind, controlled trial
Taichi Nishikawa et al. · European journal of nutrition · 2025
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Effects of quercetin ingestion on neuromuscular system following single session of resistance exercise at differing intensities in older adults
Taichi Nishikawa et al. · Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme · 2025

Editorial review

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology