Glycylglutamine

Summary

Glycylglutamine (Gly-Gln) is a naturally occurring dipeptide found in human colostrum and other biological fluids. It is more stable than free glutamine in aqueous solution and has been studied as a parenteral and enteral glutamine supplement, particularly for critically ill patients, surgical patients, and those with gastrointestinal disorders. It offers improved stability and solubility compared to free L-glutamine.

Mechanism of Action

Glycylglutamine is a stable dipeptide form of glutamine that serves as a glutamine precursor. Upon hydrolysis by peptidases, it releases glutamine and glycine, providing glutamine to tissues for protein synthesis, nitrogen transport, gluconeogenesis, antioxidant production (via glutathione), and intestinal mucosal maintenance.

Routes of Administration

Goals & Uses

• Antioxidant support (glutathione precursor)Oxidative StressLow
• Intestinal mucosal integrityGastrointestinal HealthModerate
• Glutamine supplementation in critical illnessClinical Nutrition / ICU SupportModerate
• Parenteral nutrition glutamine sourceClinical NutritionModerate
• Immune function supportImmunologyLow

Contraindications

• Severe renal failureRenal ImpairmentHigh
• Severe hepatic failureHepatic ImpairmentHigh
• Hypersensitivity to glutamine or glycineAllergyHigh

Adverse Effects

• Elevated blood urea nitrogenMetabolicUncommon
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• HyperammonemiaMetabolicRare

Drug Interactions

• Lactulose / ammonia-lowering agentsModerate

Population Constraints

• Patients with inborn errors of amino acid metabolismGenetic/metabolicAbsolute
• Pediatric patientsAgeRelative
• Pregnant or lactating womenReproductiveRelative

Regulatory Status

• European UnionUnapprovedNot EMA-approved. Used in research contexts.
• United StatesUnapprovedNot FDA-approved as a drug. May be used as a research compound or dietary supplement ingredient.
• United KingdomUnapprovedNot MHRA-approved as a medicinal product.

Not independently approved by FDA, EMA, or other major regulatory agencies as a drug. Used primarily in research settings. Related glutamine dipeptides (e.g., alanyl-glutamine) have broader clinical use. Glycylglutamine may be available as a research chemical or nutritional supplement ingredient.

Evidence & Sources

No sources recorded yet.