ALSOFOUNDINMSG (Monosodium glutamate)
Myth CorrectedThe panic was wrong. The labeling rules still aren't. Also listed on labels as Monosodium glutamate, E621, Ajinomoto.
E-number: E621
What it is
The sodium salt of glutamic acid — an amino acid your body makes and that occurs naturally in tomatoes, parmesan, mushrooms, and seaweed. A Japanese chemist isolated it from kombu in 1908 and named the taste it produced: umami.
Why it's in food
It delivers savory depth for pennies, and it does something manufacturers rarely advertise — MSG carries about a third the sodium of table salt, so it's often used to cut sodium while keeping food tasting full. Broth, chips, seasoning blends, and fast food all lean on it.
US vs EU status
United States
FDA GRAS, and it must be declared as 'monosodium glutamate' when added directly. The gap is what doesn't have to say it: hydrolyzed protein, autolyzed yeast extract, and soy protein isolate all deliver free glutamate — the same molecule doing the same job — under different names. The FDA does bar 'No MSG' claims on foods containing those ingredients, which is a quiet admission of how the loophole works.
European Union
Permitted as E621 — and here the EU moved in the opposite direction from the American narrative. In 2017 Europe's regulator re-evaluated glutamates and, for the first time, set a numeric daily limit of 30 mg per kilogram of body weight, noting that some people, especially children, could exceed it. The US relaxed its suspicion around the same years Europe added a number.
Common products
- Seasoning blends, bouillon cubes, and instant soups
- Chips, crackers, and snack seasonings
- Fast food — fried chicken and sauces in particular
- Frozen dinners and canned soups
- 'No MSG' products, via yeast extract or hydrolyzed protein
- Naturally: parmesan, tomatoes, mushrooms, soy sauce, breast milk
Cleaner swaps
- Nothing, if the concern was safety — the evidence doesn't support avoiding it
- Real umami: parmesan, dried mushrooms, tomato paste, miso, anchovy
- Reading for yeast extract if you're avoiding it anyway
Case note
MSG earns a gold stamp because a board that only convicts isn't investigating. The panic was built on one 1968 letter and never survived blinded testing. What survives is the labeling: the same molecule hides behind yeast extract, and Europe put a number on it in 2017 while America was still arguing about a myth.
Read the full investigation: Is MSG Actually Bad for You? We Opened the File →
FAQ
Is MSG bad for you?
Decades of double-blind trials have failed to reproduce the symptoms the panic was built on. The FDA acknowledges that some people report short-term effects — headache, flushing — from large doses taken without food, and calls MSG safe at normal levels. Regulators worldwide agree. This is one of the few files on this board where the honest answer is that the accusation didn't hold up.
Where did the MSG scare come from?
A 1968 letter to a medical journal describing symptoms after Chinese restaurant meals, which the press turned into 'Chinese Restaurant Syndrome.' The studies that followed didn't confirm it, and the framing has since been widely criticized for singling out one cuisine while the same additive sat in ranch dressing and canned soup. Merriam-Webster revisited its dictionary entry in 2020.
Why do some labels say 'No MSG' but list yeast extract?
Because that's legal. Autolyzed yeast extract, hydrolyzed protein, and soy protein isolate all supply free glutamate without triggering the MSG declaration. The FDA prohibits 'No MSG added' claims on those products — but 'No MSG' language and the general impression persist. The molecule doesn't change; the label does.
Is added MSG the same as glutamate in tomatoes?
Chemically, your body can't tell them apart — free glutamate is free glutamate whether it came from a parmesan rind or a shaker. That's the strongest argument in MSG's defense, and it cuts both ways: it also means 'naturally occurring' isn't the safety distinction people assume it is.
How the FDA decides what reaches your table and your medicine cabinet — and how it learned to decide.
Related files
Natural Flavors Natural flavoring
Two words that can hide dozens of undeclared ingredients.
Open file →Red 40 Allura Red AC
Legal in the US. Child-behavior warning in Europe.
Open file →Aspartame NutraSweet
WHO calls it a 'possible carcinogen.' The FDA disagrees.
Open file →Carrageenan Irish moss extract
Seaweed-derived. The gut-inflammation fight won't die.
Open file →