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Kinetics and metabolic effects of orally administered ornithine alpha-ketoglutarate in healthy subjects fed with a standardized regimen

Cynober L, Vaubourdolle M, Dore A, Giboudeau J

The American Journal of Clinical Nutrition 1984 39(4):514-519

Bibliography

PubMed: PMID 6369955
DOI: 10.1093/ajcn/39.4.514
Funding: Funding details are not provided in the PubMed record reviewed for this entry.
Competing interests: This historical paper predates modern standardized competing-interest reporting.

Design	Controlled oral metabolic study.
Model	Healthy adults on a standardized diet.
Sample	10 participants received OKG; 6 control participants received water.
Intervention	Oral ornithine alpha-ketoglutarate.
Duration	Acute post-dose metabolic observation.
Endpoints	Plasma ornithine; Plasma AKG; Urinary amino acids and AKG; Insulin; Glucose; Urea

This early human study is included as related-form evidence for the AKG-forms and Ca-AKG-vs-AAKG/OKG architecture, not as Ca-AKG efficacy evidence.

Oral ornithine alpha-ketoglutarate was rapidly metabolized and changed insulin, glucose and amino-acid handling in healthy participants.

Because ornithine has independent metabolic effects, OKG findings cannot be assigned to the AKG moiety or transferred directly to Ca-AKG.

OKG was rapidly metabolized after oral administration.
The intervention altered insulin, glucose and amino-acid profiles.
Plasma AKG itself did not simply mirror the administered OKG dose, illustrating formulation/metabolic complexity.

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Last verified 20 September 2026