L-Glutamine
Commonly used for
Athletic Performance
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The cheapest product is usually low quality, but more expensive doesn’t always mean better.
What is it? / Overview
Glutamine is a fuel source for intestinal and immune cells and becomes conditionally essential during severe physical stress, illness, or gut-lining disruption. Its role as intestinal-cell fuel is a mechanistic rationale, not proven benefit for nonspecific digestive symptoms or routine training recovery.
How is it used? / Administration
Form: L-Glutamine powder or capsules
Typical dose studied: 5–10 g/day
Timing: Post-workout or on an empty stomach
Downgraded to emerging — clinical benefit is context-dependent (specific disease, injury, severe physical stress) rather than broadly established for routine training recovery or general digestive complaints.
How well does it work? / Evidence
? Emerging / limited evidence
Who should avoid it?
Avoid with: Cancer — active or within past 12 months; End-stage liver disease / Cirrhosis
Already taking it? Evidence for routine athletic or general gut-support use is limited and context-dependent — benefit is best established in specific illness/injury/severe-stress settings, not nonspecific digestive symptoms.
Research & references
Rondanelli M et al. Glutamine and intestinal health — review. Legault Z et al. Glutamine and exercise-induced muscle damage.
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