Skip to main content
SupplementScience

Types of Glutamine: Forms & Bioavailability

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest For
L-Glutamine PowderModerate (substantial first-pass gut uptake)Most common and cost-effective — much of oral glutamine is consumed by gut enterocytes before reaching circulation
Alanyl-Glutamine (Sustamine)Higher (peptide form)Improved stability and absorption — dipeptide form resistant to gut metabolism; better for raising plasma levels
Glutamine PeptidesModerate-HighProtein-bound form — may be more stable and better absorbed than free-form L-glutamine

L-Glutamine Powder

Bioavailability: Moderate (substantial first-pass gut uptake). Best for: Most common and cost-effective — much of oral glutamine is consumed by gut enterocytes before reaching circulation.

Alanyl-Glutamine (Sustamine)

Bioavailability: Higher (peptide form). Best for: Improved stability and absorption — dipeptide form resistant to gut metabolism; better for raising plasma levels.

Glutamine Peptides

Bioavailability: Moderate-High. Best for: Protein-bound form — may be more stable and better absorbed than free-form L-glutamine.

Full Glutamine Guide

References

  1. (). Does glutamine have a role in reducing infections in athletes?. European Journal of Applied Physiology. DOI
  2. (). Effect of glutamine supplementation combined with resistance training in young adults. European Journal of Applied Physiology. DOI
  3. (). Glutamine supplementation in serious illness: a systematic review of the evidence. Critical Care Medicine. DOI