E621 · Flavour enhancers

Monosodium glutamate

Moderate risk flavour enhancerumami

Flavor enhancer; sensitivity reactions in some people.

Category: Flavour enhancers
Acceptable daily intake: 30 mg/kg body weight/day (EFSA)
Vegan: Yes
Vegetarian: Yes

What it is

Monosodium glutamate (E621) is the sodium salt of glutamic acid, one of the most abundant naturally occurring non-essential amino acids. It is used in the food industry to enhance savory flavors and provide "umami", the fifth basic taste.

How it is used in food

The pure form of umami.

Commonly found in

Salty snacks and potato chips
Instant noodles and soups
Seasoning blends and bouillon cubes
Processed meats and frozen meals
Restaurant food (particularly East Asian cuisine)

Health and safety

A minority do react to large doses. It makes ultra-processed food very easy to overeat.

MSG is one of the most intensely studied food additives in history. Decades of scientific research have repeatedly debunked the existence of "Chinese Restaurant Syndrome". While a tiny minority of people may have a mild sensitivity to large doses consumed on an empty stomach, it is safe for the general public.

MSG symptom complex (Headaches)

sensitive individuals · evidence: suspected

A very small subset of the population reports mild, short-term symptoms (headache, flushing, sweating) after consuming large doses of MSG without food. However, extensive double-blind studies have consistently failed to confirm a reliable link between MSG and these symptoms.

FDA Questions and Answers on MSG

Sodium reduction

general population · evidence: established

Because MSG contains about one-third the sodium of table salt, it can actually be used to reduce the overall sodium content of foods while maintaining flavor.

FDA Questions and Answers on MSG

EFSA set a formal intake limit in 2017 — mostly exceeded by heavy snack diets.

Regulatory status

Region	Status	Notes
Australia & New Zealand FSANZ	Permitted	Permitted.
European Union EFSA / European Commission	Permitted	Authorised for food use under EU regulations (Annex II).
United States FDA (Food and Drug Administration)	Permitted	Generally Recognized as Safe (GRAS).

Identification on labels

E-number: E621

Also printed asmsg

Alternatives to this additive

E627: Disodium guanylate — Provides umami synergy.
E631: Disodium inosinate — Provides umami synergy.
Yeast extract — Naturally rich in glutamates and used by clean-label brands to provide umami without listing E621.

How it is made

Originally extracted from seaweed, modern MSG is produced industrially through the bacterial fermentation of starch, sugar beets, sugar cane, or molasses, a process very similar to making yogurt or vinegar.

Preparation — A carbohydrate source (like tapioca, sugar cane, or molasses) is prepared into a nutrient broth.
Fermentation — Corynebacterium glutamicum bacteria are added and allowed to ferment the sugars, excreting glutamic acid.
Separation — The glutamic acid is separated from the fermentation broth and purified.
Neutralisation — The glutamic acid is neutralized with sodium hydroxide to form monosodium glutamate.
Crystallisation — The liquid is evaporated to form pure MSG crystals.

Worth knowing

Identified in 1908 from kombu seaweed broth. Glutamate itself is in parmesan, tomatoes and breast milk.

Conclusion

E621 (MSG) is a safe, highly effective flavour enhancer. It is metabolized by the body in exactly the same way as the natural glutamates found in tomatoes, cheese, and mushrooms.

References

EFSA evaluation of E621 — EFSA
EFSA re-evaluation of glutamic acid and glutamates — EFSA
EFSA glutamates re-evaluation (2017) — EFSA
FDA Questions and Answers on MSG — FDA

Is it in what you are buying?

ScanWise reads the barcode and tells you which additives a product actually contains, and what they do to its score.

Open the app

Entry last reviewed 2026-07-28.

← All additives