Is E621 Monosodium Glutamate (MSG) Safe to Eat? The Real Science

Few food additives have a reputation like E621, monosodium glutamate, better known as MSG. For decades it has been blamed for everything from headaches to numbness, yet it is also one of the most thoroughly studied ingredients in the world. Here is what MSG actually is and what the science genuinely shows. For more, see our food additives guides.

What is E621 monosodium glutamate?

MSG is the sodium salt of glutamic acid, the natural amino acid behind umami, the savoury fifth taste. It is made by fermenting starches or sugars with bacteria, the same kind of process used to brew vinegar or culture yoghurt. The result is a white crystalline powder that dissolves easily and delivers a clean savoury hit.

Glutamate itself is everywhere in food: it is abundant in Parmesan, ripe tomatoes, mushrooms, soy sauce, seaweed, and cured meats. In fact, the dish that first made glutamate famous was Japanese dashi broth made from kombu seaweed. Your body treats the glutamate in MSG exactly the same way it treats the glutamate in a tomato.

What does it do in food?

MSG is a flavour enhancer. It does not have a strong taste alone but it amplifies savoury, meaty, brothy flavours, making food taste fuller. Cooks and manufacturers use it to:

• Deepen the savouriness of soups, stocks, and ramen.
• Make crisps, snacks, and seasonings more moreish.
• Round out sauces, gravies, and ready meals.

Interestingly, because MSG delivers savoury satisfaction with about a third of the sodium of table salt, it can be used to reduce the total salt in a recipe while keeping it tasty.

Is MSG safe to eat?

Yes, for the general population. MSG is approved in the European Union, the United Kingdom, and the United States, where the FDA has classified it as Generally Recognised As Safe for decades. The European Food Safety Authority reviewed it in 2017 and set a precautionary group Acceptable Daily Intake, but normal dietary use falls well within that limit.

What about Chinese Restaurant Syndrome?

The fear of MSG largely began with a single 1968 letter to a medical journal describing symptoms after Chinese meals, which the media dubbed Chinese Restaurant Syndrome. Since then, numerous rigorous double-blind trials, where neither participants nor researchers knew who got MSG, have failed to reliably reproduce these symptoms. The consensus among food-safety authorities is that there is no consistent evidence that MSG causes the reactions long attributed to it in the general population.

A small minority of people self-report sensitivity to very large doses on an empty stomach and may choose to limit intake, but this is far from the widespread danger the additive was once thought to pose. Much of MSG's bad reputation is now recognised as having cultural rather than scientific roots.

Foods that commonly contain E621

You will find MSG in savoury snacks, instant noodles, stock cubes, soups, seasonings, sauces, processed meats, and many takeaway and ready meals. The same glutamate is naturally present in aged cheese, tomatoes, mushrooms, and fermented foods.

The bottom line

E621 monosodium glutamate is simply the sodium salt of a natural amino acid, made by fermentation and chemically identical to the glutamate in everyday foods. It is judged safe by EFSA, the FDA, and the UK Food Standards Agency, and the famous symptoms once blamed on it have not been confirmed in controlled studies. It even contains less sodium than table salt. For most people, MSG is a safe and effective way to make food taste better.