Monosodium glutamate

Monosodium glutamate (MSG) is a flavor enhancer added to foods to impart a savory “umami” taste. It is the sodium salt of the amino acid glutamate, found naturally in tomatoes, cheese, and other foods. Regulatory authorities like the FDA consider MSG generally safe. However, a small fraction of people report short-term symptoms (such as headache or flushing) after eating a large MSG-heavy meal. Scientific studies have not confirmed any widespread or lasting harm from MSG at the amounts used in food

Aliases / Common Names: MSG; Monosodium L-glutamate; Sodium glutamate; INS/E 621 Regulatory Status & Exposure: In the U.S., MSG is on the FDA’s GRAS (Generally Recognized as Safe) list for food additives. Foods that contain added MSG must list it on the ingredient label as “monosodium glutamate”. No specific upper limit is set by FDA, but typical consumption (~0.5 grams/day) is far below amounts used in toxicity studies. The European Union permits MSG (E621) in many foods, generally up to 10 g/kg, and EFSA has established a group Acceptable Daily Intake of 30 mg per kg body weight. High consumers (especially children) who eat a lot of MSG-rich foods could exceed this ADI, prompting EFSA to urge lower allowable levels in certain foods. Notably, many countries prohibit added MSG in infant foods as a precaution, after early animal studies raised concerns for developing brains. Nevertheless, no country has banned MSG in foods for older children or adults, and global bodies (WHO/JECFA) found no toxicological risk at normal intake levels (assigning it an ADI “not specified”). Technical Evidence: MSG’s main component, glutamate, is a normal amino acid that the body metabolizes just like glutamate from protein. It does not readily enter the brain from the bloodstream under normal conditions, mitigating earlier fears about “excitotoxic” brain damage. High-dose studies in baby mice from the 1960s did find neuron damage, spurring removal of MSG from baby foods, but those doses were far above typical human exposures. Extensive research in humans – including placebo-controlled trials – has generally failed to reproduce severe reactions. In a rigorous multi-center trial, even subjects who believed they were MSG-sensitive did not show consistent symptoms when blinded to MSG vs. placebo. Reported effects (headache, flushing, tingling, etc.) occur inconsistently, mainly when MSG is consumed in large amounts without other food. Some studies have explored links between very high MSG intake and metabolic or endocrine effects (like weight gain or insulin spikes), but findings are inconclusive and often involve doses or conditions not representative of normal diets. Overall, authoritative reviews (FASEB 1995, EFSA 2017, and others) conclude that MSG poses no significant health hazard to the general public at current intake levels. Fast-Food Context: Fast-food restaurants have used MSG for decades to boost the savory flavor of menu items. MSG is often added to seasoning blends for fried chicken, french fries, soups, and sauces to provide an umami-rich taste that is hard to achieve with salt alone. For example, KFC’s fried chicken recipe famously includes MSG to enhance its flavor, and other chains (like Chick-fil-A and Popeyes) have used it in certain chicken or soup items. By increasing palatability, MSG allows recipes to use less table salt while still satisfying customers’ taste for savory foods. In recent years, some fast-food companies have announced plans to reduce or eliminate added MSG in response to consumer preferences, but many savory products still contain this enhancer because of its unique flavor benefits. Sensitive Populations / Notes: A small subset of people – roughly 1–2% of the population by some estimates – may experience acute sensitivity to MSG. These individuals might develop headaches, flushed skin, or feelings of pressure/tingling after eating foods high in MSG, especially on an empty stomach. People with severe asthma have occasionally had MSG-linked bronchospasm episodes, though this is not common. Individuals who suspect they are MSG-sensitive are advised to moderate their intake or avoid eating large MSG-laden meals. It’s worth noting that glutamate also occurs naturally (in tomatoes, cheeses, mushrooms, etc.) without reports of sensitivity to those foods, suggesting that reactions – when they occur – are tied to unusually high free MSG doses. Overall sodium intake is another consideration: MSG contains sodium, but at about one-third the concentration of table salt, and its use can help lower total sodium in recipes while maintaining flavor.

We assign the limited tier using published research, regulatory guidance, and PRūF’s additive taxonomy. Restaurant usage is derived from public ingredient disclosures and mapped to menu items where this additive appears.