E621 - Monosodium glutamate

At a glance

• Role: Flavor enhancer that boosts savory, umami taste
• Also called: MSG, monosodium L-glutamate, sodium glutamate; E-number E621
• Typical uses: Snack seasonings, soups, instant noodles, sauces, frozen and canned savory foods
• Labeling: Must appear by its common or usual name “monosodium glutamate” on U.S. ingredient lists¹
• Safety: Evaluated by the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA)²³

Why is Monosodium glutamate added to food?

MSG is added to amplify umami—the savory taste found in foods like broths, meats, mushrooms, and aged cheeses. It makes flavors feel fuller and rounder without adding its own strong taste. You’ll often see it used alongside other umami-boosters such as disodium guanylate, disodium inosinate, or the blend disodium 5'-ribonucleotides.

What foods contain Monosodium glutamate?

MSG is common in:

• Savory snacks and chips
• Seasoning blends, spice packets, and bouillon
• Canned or instant soups and noodle cups
• Frozen entrees and sauces
• Processed meats and breaded products Restaurants may also use MSG in broths, sauces, and marinades. On packaged foods in the U.S., it must be listed as “monosodium glutamate” on the ingredient list.¹

What can replace Monosodium glutamate?

Depending on the recipe and dietary goals, cooks and manufacturers may use:

• Other glutamates: glutamic acid, monopotassium glutamate, calcium diglutamate
• Nucleotide umami enhancers: disodium inosinate, disodium guanylate, or disodium 5'-ribonucleotides
• Salt alternatives and flavor tools: potassium chloride, slow-roasted vegetables, mushrooms, tomato paste, seaweed, soy sauce, miso, and long-simmered stocks

How is Monosodium glutamate made?

Modern MSG is typically produced by fermentation. Food-grade microbes convert sugars or starches (for example, from sugar cane, sugar beets, or molasses) into glutamic acid, which is then neutralized and crystallized with sodium to form MSG.² The process is similar to making other fermented ingredients and is controlled to meet food-grade purity specifications.²

Is Monosodium glutamate safe to eat?

• United States: The FDA classifies MSG as safe for its intended use and continues to monitor its safety. Decades of studies have not shown consistent evidence of harm for the general population when MSG is consumed in normal amounts.²
• European Union: EFSA set a group Acceptable Daily Intake (ADI) of 30 mg/kg body weight per day, expressed as glutamic acid, for glutamate additives (E 620–E 625), including E621.³

In the U.S., MSG must be declared by its common or usual name on ingredient labels; it cannot be hidden under the word “spices” or “flavorings.”¹

Note: GRAS means “Generally Recognized As Safe,” a U.S. regulatory category for substances widely known, through scientific procedures or experience, to be safe under the conditions of their intended use.

Does Monosodium glutamate have any benefits?

• Flavor building: A small amount can noticeably increase savory depth and roundness, helping foods taste richer and more satisfying.
• Menu development: Chefs often use umami to balance dishes so that less added salt is needed for the same perceived savoriness.
• Consistency: MSG delivers a reliable umami lift, batch after batch, unlike some natural ingredients that can vary seasonally.

Who should avoid Monosodium glutamate?

• Individuals who notice they are sensitive: A small number of people report short-lived symptoms (such as flushing or headache) when consuming foods high in added glutamate. If you suspect sensitivity, discuss it with a healthcare professional and read labels carefully.
• Those managing total intake: EFSA’s ADI applies to total exposure from all glutamate additives; high consumers, especially children with frequent intake of heavily seasoned foods, can exceed the ADI and may wish to limit use.³
• Sodium-restricted diets: MSG contains sodium. While it contributes umami rather than saltiness alone, people tracking sodium should consider all sources.

Myths & facts

• Myth: “MSG is the same as gluten.”
  Fact: MSG is a sodium salt of the amino acid glutamic acid; gluten is a protein found in wheat and some other grains.
• Myth: “MSG adds a strong meaty flavor by itself.”
  Fact: MSG doesn’t taste meaty; it boosts the underlying savory notes already present in the dish.
• Myth: “MSG is always hidden on labels.”
  Fact: In the U.S., “monosodium glutamate” must be named explicitly in the ingredient list; it cannot be grouped under “spices” or “flavorings.”¹

Monosodium glutamate in branded foods

MSG shows up across many grocery categories: snack chips and seasonings, dry soup mixes, instant noodles, frozen dinners, sauces, and some processed meats. To find it, scan the ingredient list for “monosodium glutamate” or “MSG.” You may also see related flavor enhancers such as disodium inosinate, disodium guanylate, or disodium 5'-ribonucleotides.

References

Footnotes

1. Food; designation of ingredients (21 CFR 101.4) — U.S. Government Publishing Office (eCFR). https://www.ecfr.gov/current/title-21/section-101.4 ↩ ↩² ↩³ ↩⁴

2. Questions and Answers on Monosodium Glutamate (MSG) — U.S. Food and Drug Administration. https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg ↩ ↩² ↩³ ↩⁴

3. Re-evaluation of glutamic acid (E 620), sodium glutamate (E 621), potassium glutamate (E 622), calcium diglutamate (E 623), monoammonium glutamate (E 624) and magnesium diglutamate (E 625) as food additives — European Food Safety Authority (EFSA). https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2017.4910 ↩ ↩² ↩³