Tier 2 — strong

Disposition of quercetin in man after single oral and intravenous doses

R Gugler, M Leschik, H J Dengler
European journal of clinical pharmacology 1975 9(2-3):229-34

Bibliography

PubMed
PMID 1233267
DOI
10.1007/BF00614022
Funding
Funding was not specified in the indexed record or the disclosure metadata available for this entry.
Competing interests
A competing-interest declaration was not available in the indexed record or the disclosure metadata used for this entry.

Study snapshot

DesignEarly human oral and intravenous disposition study
ModelHuman intervention research
Sample6 volunteers
InterventionQuercetin 4 g orally or 100 mg intravenously
DurationSingle-dose comparisons
EndpointsExposure and pharmacokinetics

What the study showed, in plain terms

Published in 1975, this source examined forms, absorption and food sources. Design: Early human oral and intravenous disposition study. Sample/model: 6 volunteers. The exposure or intervention was Quercetin 4 g orally or 100 mg intravenously. Follow-up or treatment period: Single-dose comparisons.

The older assay detected rapid intravenous disposition but no measurable oral plasma quercetin; fecal recovery suggested extensive gut metabolism.

Historical methods measured different analytes with less sensitivity than later metabolite studies. The result should not be presented as proof that modern oral quercetin is never absorbed.

Continue with Quercetin Data Center

For topic-level interpretation, read Quercetin Forms: Dihydrate, Phytosome, Liposomal and Glycosides. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • The older assay detected rapid intravenous disposition but no measurable oral plasma quercetin; fecal recovery suggested extensive gut metabolism.
  • The recorded outcome domains were Exposure and pharmacokinetics.
  • The result applies to the tested exposure: Quercetin 4 g orally or 100 mg intravenously; Single-dose comparisons.

What this study can and cannot tell us

  • Historical methods measured different analytes with less sensitivity than later metabolite studies. The result should not be presented as proof that modern oral quercetin is never absorbed.
  • 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.
  • Source basis: Source check: PubMed abstract and indexed metadata; full methods were not independently confirmed for this entry. Missing method details, funding information or participant denominators are not inferred.

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Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

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