E640 Glycine

E640Flavor enhancersOrigin: Lab-made

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Every diet

VeganYes

Synthetic or fermented; no animal ingredients.

Gluten-freeYes

HalalYes

KosherYes

KetoYes

Low-FODMAPYes

The short answer

Glycine (E640) is the smallest amino acid, and it adds a faintly sweet, savory note to flavor blends. It is one of the safest additives on the list.

90/100

Generally safe

Fine for most people at normal amounts.

E-numberE640

Comes fromLab-made

What it doesFlavor enhancers

Glycemic index—

Daily limitNot set

Also calledGlycine, Aminoacetic acid

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved with limits

🇨🇦 Health CanadaApproved with limits

CaliforniaNo extra rules

Generally recognized as safe in the US as an amino acid ingredient. The EU allows it as a flavor enhancer in listed foods. It is also a common supplement ingredient, and no daily limit has been set for food uses.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Glycine is a white, sweet-tasting powder. It is found in collagen and in many everyday proteins. In food it softens sharp flavors and adds a little sweetness, so it is often used alongside sugar substitutes.

Where it comes from: The simplest amino acid. It is made by chemical synthesis or by fermentation, and the body makes its own supply as well.

Why it’s in food

Softens sharp or bitter tastes
Adds mild sweetness
Used in sugar-free blends
Common in protein supplements

Often found in

Sugar-free sweetener blendsSavory seasoning mixesProtein drinks and powdersFlavored waterVitamin gummies

Also listed as: Glycine, Aminoacetic acid, Glycocoll, Amino acetic acid

Health & gut impact

Body's own supplyBenefit

The body makes glycine from other amino acids and uses it to build collagen, so modest amounts from food are normal.

NIH Office of Dietary Supplements

Large dosesUnder study

Supplement doses of several grams a day are studied for sleep and muscle, and food uses are far smaller than those amounts.

EFSA Panel on Food Additives

Sweeten without amino acid blends

Clean-label swaps

Clean substitute

Pure stevia powder

A single-ingredient plant sweetener.

Shop pure stevia powder Opens your country’s Amazon store

Clean grocery swap

Honey, single ingredient

Real sweetness without a blend.

Shop raw honey Opens your country’s Amazon store

Pantry staple

Plain cane sugar

Simple sugar with nothing added.

Shop cane sugar Opens your country’s Amazon store

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What can I use instead?

Stevia

Ratio: To taste

Best for: Sugar-free sweetness

Plain sugar

Ratio: 1:1

Best for: Sweetness without amino acids

More flavor enhancers:

Disodium Guanylate E627Disodium guanylate (E627) is a savory booster used with MSG. It's usually made from yeast, but can come from fish, so check for a vegan label.Generally safe Disodium Inosinate E631Disodium inosinate (E631) boosts savory flavor, usually alongside MSG. It's often made by fermentation but can come from meat or fish, so it's only reliably vegan when labeled.Generally safe Disodium ribonucleotides (I+G) E635Disodium ribonucleotides (E635) are a 50/50 mix of two flavor boosters that make MSG taste much stronger. They're safe for most people, but their source isn't always vegan or halal.Generally safe Glutamic acid E620Glutamic acid (E620) is the amino acid behind the savory taste of MSG. Made by fermentation, it is safe in food and is common in protein, though it is rarely sold on its own.Generally safe

Common questions

Is glycine safe to eat every day?

Yes, in food amounts. It is an amino acid the body already makes and uses for protein and collagen.

Is Glycine safe?

Generally safe (90/100). Generally recognized as safe in the US as an amino acid ingredient. The EU allows it as a flavor enhancer in listed foods. It is also a common supplement ingredient, and no daily limit has been set for food uses.

Is Glycine vegan?

Yes. Synthetic or fermented; no animal ingredients.

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Scientific sources & regulatory citations

EFSA OpenFoodTox: E640
NIH Office of Dietary Supplements
EFSA Panel on Food Additives

INS 640 · CAS 56-40-6