Monosodium glutamate (MSG; E621) in food: ingestion safety
Low risk(People-specific data is limited; this page draws from human adult context.) Monosodium glutamate (E621) presents low risk to human adults at typical dietary exposure. FDA GRAS; EFSA 2017 established ADI 30 mg/kg/day (1,800 mg/day for a 60kg adult) — the first numerical ADI for glutamates, based on animal toxicology endpoints, not CRS. Double-blind challenge studies have consistently failed to reproduce 'MSG symptom complex' at dietary doses, establishing scientific consensus that CRS is not causally linked to MSG at typical intake. Dietary glutamate does not significantly raise brain glutamate concentrations under normal blood-brain barrier function. Heavy Asian cuisine consumers may approach the EFSA ADI from combined sources. No carcinogenicity classification.
What is monosodium glutamate (msg; e621)?
The IUPAC name is sodium;(4S)-4-amino-5-hydroxy-5-oxopentanoate;hydrate.
Also known as: sodium;(4S)-4-amino-5-hydroxy-5-oxopentanoate;hydrate, MSG monohydrate, MONOSODIUM GLUTAMATE, Ancoma.
- IUPAC name
- sodium;(4S)-4-amino-5-hydroxy-5-oxopentanoate;hydrate
- CAS number
- 142-47-2
- Molecular formula
- C5H10NNaO5
- Molecular weight
- 187.13 g/mol
- SMILES
- C(CC(=O)[O-])C(C(=O)O)N.O.[Na+]
- PubChem CID
- 23689119
Risk for people
Low riskMonosodium glutamate (E621) presents low risk to human adults at typical dietary exposure. FDA GRAS; EFSA 2017 established ADI 30 mg/kg/day (1,800 mg/day for a 60kg adult) — the first numerical ADI for glutamates, based on animal toxicology endpoints, not CRS. Double-blind challenge studies have consistently failed to reproduce 'MSG symptom complex' at dietary doses, establishing scientific consensus that CRS is not causally linked to MSG at typical intake. Dietary glutamate does not significantly raise brain glutamate concentrations under normal blood-brain barrier function. Heavy Asian cuisine consumers may approach the EFSA ADI from combined sources. No carcinogenicity classification.
Regulatory consensus
3 regulatory and scientific bodies have classified Monosodium glutamate (MSG; E621). The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 2017 | Not evaluated by IARC for carcinogenicity — Monosodium glutamate (MSG; E621; CAS 142-47-2; the sodium salt of L-glutamic acid) is one of the most extensively studied food additives globally and is classified GRAS by FDA (21 CFR 182.1) and assigned ADI 'not specified' by EFSA (2017 re-evaluation) and JECFA; no IARC, EPA, or EFSA carcinogenicity classification; the dominant safety controversy surrounding MSG is the so-called 'Chinese Restaurant Syndrome' (CRS) or 'MSG symptom complex' — a cluster of self-reported symptoms (headache, facial flushing, sweating, chest tightness, numbness) attributed to MSG consumption; double-blind, placebo-controlled clinical studies have consistently failed to reproduce these symptoms reliably when subjects consume MSG without knowing it, leading to scientific consensus that CRS at typical dietary doses is not causally attributable to MSG; L-glutamate is the most abundant amino acid in the human body and a key excitatory neurotransmitter, but dietary glutamate does not cross the blood-brain barrier in significant quantities under normal conditions; glutamate is naturally present at high concentrations in parmesan cheese (1,200 mg/100g), soy sauce (1,100 mg/100g), tomato paste (360 mg/100g), anchovies (630 mg/100g), and mushrooms (180 mg/100g) — foods consumed without reported adverse effects | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 8 positive / 7 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 8 positive / 7 negative reports) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where you encounter monosodium glutamate (msg; e621)
- Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
- Occupational Environments — Factories, Warehouses, Transportation vehicles
- Food — processed food, beverages, candy, baked goods
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Monosodium glutamate (MSG; E621):
-
Natural preservatives; Clean-label ingredients; Minimally processed food
Trade-offs: Consumer label appeal ('clean label'); variable efficacy depending on food matrix and target pathogen; may alter flavor/color; regulatory status varies by jurisdiction; often more expensive per unit of preservation effect.Relative cost: 2-5× conventional
Frequently asked questions
What products contain monosodium glutamate (msg; e621)?
Monosodium glutamate (MSG; E621) appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); processed food (Food).
Why do regulators disagree about monosodium glutamate (msg; e621)?
Monosodium glutamate (MSG; E621) has been classified by 3 agencies including IARC, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Monosodium glutamate (MSG; E621) in the food app
Look up products containing monosodium glutamate (msg; e621), compare to alternatives, and explore the full data record.
Open in food View raw API dataSources (1)
- MSG E621 CAS 142-47-2 L-Glutamate Sodium Salt C5H8NNaO4 Umami T1R1+T1R3 GPCR; EFSA 2017 ADI 30 mg/kg/day First Numerical Glutamate ADI EFSA Journal 2017;15(7):4910 Animal Toxicology Not CRS; FDA GRAS 21 CFR 182.1 ADI Not Specified Historical; Ikeda 1908 Kombu Umami T1R1 T1R3; Kwok 1968 NEJM Letter Chinese Restaurant Syndrome Unblinded Self-Report; FASEB 1995 FDA-Commissioned No CRS ≥3g Aqueous Not Food Dose; Shi 2016 Crit Rev Food Sci Nutr Meta-Analysis No Double-Blind Replication; Nocebo Expectation Bias; Blood-Brain Barrier Excludes Peripheral Glutamate Normal BBB Function; Olney 1969 Subcutaneous 1-4g/kg Mice Irrelevant Oral; Natural: Parmesan 1200 Soy Sauce 1100 Anchovies 630 Marmite 1400 mg/100g; Corynebacterium Glutamicum Fermentation 3.5M Tonnes/Year; IMP GMP Synergy Umami Amplification (2017) — regulatory
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →