Disodium guanylate
A flavour enhancer derived from guanylic acid, used alongside glutamates to intensify savoury taste. Avoided by people managing gout.
Breaks down to purines in the body, which raise uric acid levels. Regular intake can worsen gout or contribute to uric acid kidney stones in people prone to them.
What is it?
Disodium guanylate (GMP, guanosine 5'-monophosphate disodium salt) is the sodium salt of guanylic acid, a naturally occurring nucleotide found in RNA. It is produced commercially by enzymatic digestion of yeast extract or dried fish (such as dried bonito or sardines), then purified. It appears as a white crystalline powder with little flavour of its own.
What does it do?
Guanylate acts on the same umami taste receptors as glutamates, binding to the T1R1/T1R3 receptor complex on the tongue. It has a synergistic effect with monosodium glutamate (E621): even small amounts of E627 dramatically amplify the perceived intensity of glutamate, allowing manufacturers to use less MSG overall while achieving a stronger savoury taste. It does not create umami flavour independently at the concentrations used in food; its role is amplification.
Where you will see it
Instant noodles and packet soups, savoury snacks and crisps, stock cubes and bouillon powders, seasoning blends, processed meats, flavoured crackers, ready meals, and powdered sauce mixes. It is almost always used in combination with E621 (MSG) or E631 (disodium inosinate), rarely alone. On UK labels it appears as 'disodium guanylate', 'flavour enhancer (627)', or 'guanylate'.
What the science says
Purine load and uric acid
Disodium guanylate is a purine nucleotide. When digested, it is broken down to guanosine and then to uric acid. In people who already excrete or produce excess uric acid, extra dietary purines from nucleotide additives can raise serum urate levels and precipitate or worsen gout attacks. The contribution from food-additive nucleotides is additive with purines from red meat, organ meat, and certain fish.
Dietary purines, including nucleotide additives such as GMP and IMP, are metabolised to uric acid in humans; elevated serum urate is a prerequisite for gout and uric acid nephrolithiasis.
UK gout management guidance recommends that people with gout or hyperuricaemia reduce intake of purine-rich foods and purine-containing additives.
Nucleotide additives and the broader MSG sensitivity question
E627 is almost always used alongside glutamate enhancers. Some people attribute headaches or flushing to products containing this combination. Controlled studies have not established that nucleotide additives alone cause these effects at food-use concentrations; the evidence linking the nucleotide component specifically, rather than the glutamate, is weak. However, because E627 is rarely used without glutamates, it is practically inseparable from glutamate-containing products on a real-world label.
Double-blind trials of MSG at doses equivalent to a typical meal found no consistent adverse effects in self-reported MSG-sensitive individuals; the contribution of co-present nucleotide enhancers was not isolated.
Regulatory safety review
The European Food Safety Authority (EFSA) Panel on Food Additives and Nutrient Sources reviewed nucleotide flavour enhancers (E626-E635) and set a group acceptable daily intake. No genotoxicity, carcinogenicity, or reproductive concerns were identified. The Panel's concern was limited to purine load and its metabolic consequences in susceptible individuals.
EFSA established a group ADI of 4 milligrams per kilogram of bodyweight per day for the guanylic acid/guanylate group (E626-E629), based on the purine load to uric acid and effects in susceptible individuals.
Dietary exclusions: fish and yeast origin
Commercial disodium guanylate is typically derived from yeast extract or fish. This means it is not suitable for vegans or strict vegetarians (depending on the source), and could be a hidden source of fish for people with fish allergies, depending on how thoroughly it is purified. UK and EU labelling rules require fish to be declared as an allergen only when fish protein remains at a level that could cause a reaction; highly purified nucleotides may fall below this threshold in practice, but the origin is not always declared.
Disodium guanylate is produced industrially from dried fish or yeast RNA; the presence of residual fish protein in finished product depends on the purification process and is not consistently declared on consumer labels.
Where it stands with the regulators
Who should be careful
People with gout, hyperuricaemia (high uric acid), or a history of uric acid kidney stones. Vegans and vegetarians should be aware it is commonly derived from fish or yeast; check with the manufacturer if source matters. People with a fish allergy who react to trace amounts should treat any product containing E627 cautiously unless the manufacturer confirms a non-fish source. Look for 'disodium guanylate', 'flavour enhancer (627)', or 'E627' on the label.
The honest read
For the general population without gout or uric acid issues, disodium guanylate is a well-characterised nucleotide that humans digest via the normal purine pathway. The additive is found almost exclusively in heavily processed savoury products, so high intake of E627 is also high intake of that broader food category. The question of fish origin and allergen declaration is genuinely unsettled in practice: purification standards vary by manufacturer, and UK labelling law only requires fish declaration above a threshold that may not always apply to refined nucleotides. This is a live gap in allergen transparency, not a resolved one.
Related additives
Common questions
Is E627 banned in the UK?
No. Disodium guanylate is approved for use in the UK under the assimilated EU Regulation 1333/2008 framework, authorised as of 31 December 2020. It appears on the UK FSA's list of approved additives.
Can E627 trigger a gout attack?
It can contribute to one in people who are already prone to gout. Disodium guanylate is a purine nucleotide; the body breaks it down to uric acid. If you manage gout through diet, products listing E627, E631, or E635 are worth avoiding alongside high-purine foods such as red meat and organ meat.
What foods contain E627?
Mainly instant noodles, packet soups, stock cubes, savoury crisps and snack seasonings, processed meats, flavoured crackers, and ready meals. It is almost never used on its own: look for E627 appearing alongside E621 (monosodium glutamate) or E631 (disodium inosinate) on the same label.
Is E627 vegan?
Not reliably. Disodium guanylate is most commonly produced from dried fish (such as bonito or sardines) or from yeast RNA. The source is rarely declared on consumer packaging. If you follow a vegan diet or avoid fish, contact the manufacturer directly to confirm the origin before consuming products containing E627.
Sources
- UK FSA approved additives register: E627 disodium guanylate
- UK Food Standards Agency: Approved additives and E numbers
- EFSA ANS Panel: Re-evaluation of guanylic acid (E 626), disodium guanylate (E 627), dipotassium guanylate (E 628) and calcium guanylate (E 629) as food additives, EFSA Journal
- Choi HK et al. Purine-rich foods, dairy and protein intake, and the risk of gout in men, Annals of Internal Medicine
- Geha RS et al. Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate, Journal of Nutrition
- British Society for Rheumatology: Guideline for the management of gout
- JECFA monograph: Guanylic acid and its sodium, potassium and calcium salts
- EU Food and Feed Information Portal: E627 disodium guanylate
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