Monosodium glutamate

Additive · E621

Monosodium glutamate, or MSG, is a salt of glutamic acid that adds savory taste to food. Cooks use it in soups, sauces, snacks and meals. It is made by fermentation and supplies the same glutamate found naturally in many foods.

Also known as

monosodium glutamate · monosodium L-glutamate · monosodium L-glutamate monohydrate · sodium glutamate · sodium L-glutamate · L-glutamic acid, monosodium salt · glutamic acid, monosodium salt · MSG · E621 · E 621 · INS 621

Why PRūF tracks it

The review considers inconsistent symptoms after large doses without food, uncertain long-term cardiovascular evidence and EFSA exposure concerns, while a new cohort association does not establish that MSG in ordinary meals causes heart disease.

Read the research

MSG is a specific flavor enhancer. Yeast extract, protein hydrolysates and naturally occurring glutamate are different ingredient identities, even though they can supply the same glutamate molecule. Most ingested glutamate is handled by the gut before reaching the wider circulation. FDA recognizes MSG as safe for its intended use; JECFA assigned glutamates a daily intake “not specified.”

EFSA instead set a group acceptable daily intake of 30 mg glutamic acid per kilogram of body weight and identified potential exceedances, especially in younger and high-consuming groups. Exceeding this protective value does not demonstrate injury. Some people report brief symptoms after several grams without food, but repeated blinded challenges have produced inconsistent responses. Long-term evidence is less settled: Chinese weight studies disagree, and a 2026 French cohort linked higher added MSG intake with ischemic heart disease, while its overall cardiovascular result was not statistically significant and cerebrovascular disease was not associated.

This single observational study cannot establish causation. New animal lung and developmental findings also need interpretation by dose and route. Added MSG must be named on U.S. packaged-food labels; Maine and Guam require additional disclosures in specified settings.

Research reviewed on September 5, 2026 · 12 sources