E620 — Glutamic acid
E620 (Glutamic acid), a flavor enhancer, is rated "avoid": worth avoiding. The free amino acid form of glutamate, the same molecule as MSG. EFSA's 2017 re-evaluation set a group safe limit of 30 mg per kg of body weight and found that European intake exceeds it for most population groups once natural sources are counted alongside the additive.
What is Glutamic acid?
The free amino acid form of glutamate — chemically the same active molecule as MSG, just without the sodium. E620 through E625 are all this molecule paired with a different counter-ion (sodium, potassium, calcium, ammonium, magnesium). Naturally abundant in tomatoes, aged cheese, soy sauce, mushrooms, and breast milk; added to soups, sauces, stocks, and savory snacks.
What does it do to the body?
Glutamate is a normal part of your diet and your body — it is not a foreign toxin. The issue EFSA raised is dose, not identity: it set a safe intake ceiling and then found that real European diets go past it. That headroom problem is what drives the flag. The old 'MSG sensitivity' story of headaches and flushing has not held up in careful blinded trials, and is not the reason this is flagged.
What regulators say
EFSA set a group acceptable daily intake of 30 mg per kg of body weight per day (as glutamic acid) in 2017 and recommended the EU lower the permitted levels in food. It found intake exceeded that limit at both average and high consumption for all population groups except average-intake elderly — though that figure counts naturally occurring glutamate in food alongside the additive, not the additive on its own. The FDA approves it as GRAS.
Risk rating: Avoid
Known or suspected to cause harm: a substance EFSA or another regulator has flagged, or one restricted in some jurisdictions. Best kept out of a regular diet.
Source: EFSA — re-evaluation of glutamic acid and glutamates E 620–E 625 (2017) ↗