E621 — Monosodium glutamate
E621 (Monosodium glutamate), a flavor enhancer, is rated "avoid": worth avoiding. MSG, the classic umami enhancer. EFSA's 2017 re-evaluation set a group safe limit of 30 mg per kg of body weight and found European intake exceeds it for most groups — and for high-consuming children exceeds doses linked to adverse effects in human studies. The exceedance is the reason, not the old 'MSG sensitivity' folklore.
What is Monosodium glutamate?
Monosodium glutamate, the sodium salt of glutamic acid — the molecule behind the savory umami taste. E620 to E625 are the same active glutamate with different counter-ions. Found in savory snacks, instant noodles, stock cubes, broths, processed meats, seasoning blends, and widely used in restaurant cooking.
What does it do to the body?
Glutamate itself is ordinary — you eat it in parmesan and tomatoes. What EFSA flagged is that total intake now overshoots the ceiling it judged safe. It specifically noted that infants, toddlers and children at high consumption levels exceed doses associated in human studies with headache and raised blood pressure. To be clear about what this is not: the 'Chinese restaurant syndrome' panic of the 1960s has repeatedly failed to reproduce under blinded testing, and that is not the basis for this rating. The dose ceiling is.
What regulators say
EFSA set a group acceptable daily intake of 30 mg per kg of body weight per day in 2017, found exposure exceeded it for most population groups, and recommended lowering maximum permitted levels in food — a formal call to reduce it. That exposure estimate includes naturally occurring glutamate as well as the additive. The FDA approves MSG as GRAS but requires it to be declared as 'monosodium glutamate' on the label.
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) ↗