L-Glutamine | whatsinit

About

What it is and where it shows up.

L-Glutamine is a naturally occurring, conditionally essential amino acid that is the most abundant free amino acid in the human body. It is added to foods and dietary supplements as a nutritional ingredient to support gut integrity, immune function, and protein synthesis, and is also authorized as a flavouring substance in the EU.

Safety summary

The regulatory and scientific consensus.

Broadly regarded as safe at dietary and typical supplemental levels across major regulatory jurisdictions; no formal ADI has been established for L-glutamine as a standalone food ingredient. High-dose supplementation (reported above 40 g/day) may pose risks in individuals with hepatic insufficiency or epilepsy due to its role as a metabolic precursor to ammonia and excitatory neurotransmitters. The EFSA NDA Panel concluded in 2011 that a cause-and-effect relationship for specific health claims related to L-glutamine could not be established.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Authorized for use in food for nutritional purposes under Regulation (EC) No 609/2013 and as a flavouring substance (FL No 17.007). No standalone E-number assigned; not to be confused with glutamic acid (E620) or its salts (E621–E625). EFSA NDA Panel (2011) found insufficient evidence to substantiate health claims for L-glutamine.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Permitted as an amino acid ingredient in health supplements, nutraceuticals, and food for special dietary use under FSSAI Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food Regulations, 2016 (Schedule I). Suitable esters, derivatives, isomers, and salts of amino acids may be used with notification to the Food Authority.source
FDA (Food and Drug Administration) (United States)	Approved	Approved as a direct food additive for nutritional purposes under 21 CFR 172.320 (Amino Acids); also listed in the FDA Substances Added to Food (EAFUS) database. Used as a nutrient in conventional foods and dietary supplements.source

Who should approach with care

Whose guidance would steer them away.

Liver Disease — High-dose supplemental L-glutamine is metabolized to ammonia, which may exacerbate hepatic encephalopathy in individuals with compromised liver function; medical supervision is advised before use.

Epilepsy — L-glutamine is a direct metabolic precursor to glutamate, a major excitatory neurotransmitter; high supplemental doses may theoretically lower seizure threshold in people with epilepsy.

Kidney Disease — Amino acid catabolism generates nitrogenous waste; patients with impaired renal clearance may have difficulty safely excreting excess metabolites from high-dose glutamine supplementation.

Infants — FSSAI regulations specify that products for children aged 2–5 years should be given only under medical advice; adequate safety data for high-dose supplemental amino acids in infants is limited.

Ibd — While glutamine is studied for gut mucosal support, high supplemental doses in individuals with active inflammatory bowel disease should be taken under clinical supervision due to variable therapeutic outcomes and potential interactions with disease management.

Research citations

The sources behind this verdict.

1FDA. 21 CFR 172.320 – Amino Acids. accessdata.fda.gov
2FDA. Substances Added to Food (formerly EAFUS) – L-Glutamine. hfpappexternal.fda.gov
3FSSAI. Food Safety and Standards (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food) Regulations, 2016 – Compendium (September 2021), 2021. fssai.gov.in
4EFSA. Safety and efficacy of l-glutamine produced using Corynebacterium glutamicum NITE BP-02524 for all animal species, 2020. efsa.europa.eu
5PubMed. Risk Assessment Paradigm for Glutamate, 2018. pubmed.ncbi.nlm.nih.gov
6EFSA. Re-evaluation of glutamic acid (E 620), sodium glutamate (E 621), potassium glutamate (E 622), calcium glutamate (E 623), ammonium glutamate (E 624) and magnesium glutamate (E 625) as food additives, 2017.

Independently researched6 citations