Tier 4 — mechanistic

Glycine stimulated growth hormone release in man

Kasai K, Suzuki H, Nakamura T, Shiina H, Shimoda SI
Acta endocrinologica 1980 93(3):283-286

Bibliography

PubMed
PMID 7376793
DOI
10.1530/acta.0.0930283
Funding
Funding was not specified in the indexed abstract; the full funding disclosure has not been verified.
Competing interests
The accessible abstract does not establish the authors' competing interests; absence of a statement is not evidence of no conflicts.

Study snapshot

DesignExploratory human intervention
ModelHuman volunteers; intravenous administration
SampleNormal human volunteers; exact sample not specified in the indexed abstract
InterventionIntravenous glycine 4, 8 or 12 g infused over 15 or 30 minutes
DurationAcute infusion experiment
EndpointsGrowth hormone; Prolactin; Blood glucose

What the study showed, in plain terms

This historical infusion experiment found dose-dependent growth-hormone responses. Intravenous glycine is included as physiological context and must be kept separate from oral supplement evidence.

Key findings

  • Growth hormone rose after infusion, with larger responses at higher doses.
  • Prolactin did not significantly change; 12 g caused a transient glucose increase.

What this study can and cannot tell us

Intravenous exposure cannot establish effects of oral dosing.

No muscle-growth, healthy-aging or long-term safety endpoint was tested.

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Editorial review

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction