E626 Guanylic acid

E626Flavor enhancersOrigin: Fermented

Get a personal answer

Pick your family’s diets in the bar above.

Every diet

VeganDepends

Vegan when fermentation-made. Fish-derived versions are not.

Gluten-freeYes

HalalDepends

Depends on the source; certified versions are available.

KosherDepends

Depends on the source; look for a kosher certification.

KetoYes

Low-FODMAPYes

The short answer

Guanylic acid (E626) is a savory flavor booster that works with MSG to make broths and snacks taste fuller. It is safe in normal use, and people with gout may want to watch their total purine intake.

85/100

Generally safe

Fine for most people at normal amounts.

E-numberE626

Comes fromFermented

What it doesFlavor enhancers

Glycemic index—

Daily limitNot set

Also calledE626, GMP

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionApproved

🇨🇦 Health CanadaApproved

CaliforniaNo extra rules

Permitted in the US, EU and Canada as a flavor enhancer, usually paired with MSG. It is regulated with the other 5'-ribonucleotides and is often sold in blends.

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

What is it?

Guanylic acid is a nucleotide that every cell contains. Added in small amounts, it boosts the savory umami taste, and paired with MSG the effect is stronger than either one alone.

Where it comes from: Usually made by fermentation or from yeast RNA. Some producers start from fish-derived material, so the source varies by supplier.

Why it’s in food

Boosts savory flavor in chips and snacks
Adds depth to instant soups and broths
Works alongside MSG for a fuller taste
Lets makers use less salt for the same savoriness

Often found in

Instant noodlesPotato chipsStock cubesSavory snacksSeasoning blends

Also listed as: E626, GMP, Guanosine monophosphate

Health & gut impact

Gout and purinesUnder study

Nucleotides break down into uric acid. People with gout are usually advised to limit purine-rich foods, and the small amounts in flavorings add a modest share of a typical day's purines.

EFSA review of 5'-ribonucleotides

What can I use instead?

Disodium guanylate (E627)

Ratio: About 1:1 by weight

Best for: Savory blends, where the sodium counts toward salt

Disodium ribonucleotides (E635)

Ratio: About 1:1 by weight

Best for: Snack seasonings

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 guanylic acid the same as MSG?

No. MSG is glutamate, while guanylic acid is a nucleotide. They boost savory flavor together, which is why blends often include both.

Is guanylic acid vegan?

It depends on the source. Fermentation-made versions are vegan; fish-derived ones are not.

Is Guanylic acid safe?

Generally safe (85/100). Permitted in the US, EU and Canada as a flavor enhancer, usually paired with MSG. It is regulated with the other 5'-ribonucleotides and is often sold in blends.

Is Guanylic acid vegan?

Depends. Vegan when fermentation-made. Fish-derived versions are not.

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Scientific sources & regulatory citations

EFSA OpenFoodTox: E626
EFSA review of 5'-ribonucleotides

INS 626