Magnesium diglutamate
The magnesium salt of glutamic acid, added to processed food to deepen savoury taste the same way MSG does.
Children who eat a lot of processed food can take in more glutamate from additives alone than the level linked to headaches and raised blood pressure in human studies. EFSA found toddlers and children at high intake already exceed that threshold from food additives before counting the glutamate naturally present in meat, cheese, and tomatoes.
What is it?
Magnesium diglutamate is the magnesium salt of glutamic acid, an amino acid that occurs naturally in protein-rich foods such as meat, fish, cheese, and tomatoes. As an additive it is manufactured by fermentation or chemical synthesis. The magnesium ion is nutritionally inert at additive-level doses; the active part is the glutamate.
What does it do?
Glutamate activates umami taste receptors on the tongue, amplifying the perception of savoury, meaty, or brothy flavour. It does not add a flavour of its own but makes existing flavours taste fuller and more rounded. Manufacturers use it to reduce salt content or to compensate for flavour lost during industrial processing.
Where you will see it
Found in instant noodles and soups, stock cubes and bouillon powders, savoury snacks and crisps, ready meals, processed meat products, sauces, and seasonings. On a UK label it appears as 'magnesium diglutamate', 'E625', or within the group term 'flavour enhancer (E625)'.
What the science says
Dietary exposure exceeds the threshold linked to adverse effects in children
EFSA's 2017 re-evaluation found that children eating moderate to high amounts of processed food already take in more added glutamate than the dose associated with the MSG symptom complex, which includes headaches and short-term blood pressure rises in sensitive individuals. When naturally occurring glutamate from food is added on top, the group ADI is exceeded across all age groups. EFSA recommended that maximum permitted levels be cut in several food categories.
Mean dietary exposure to added glutamates in toddlers and children exceeded the dose associated with the MSG symptom complex in human studies; high-level (95th percentile) exposure in infants, toddlers, children, and adolescents surpassed doses linked to headaches and blood pressure increases.
When naturally occurring glutamate from food is included alongside additive sources, the group ADI of 30 mg/kg body weight per day is largely exceeded for all population groups.
Neurological effects at high doses in animal studies
A developmental neurotoxicity study in animals identified adverse effects on behaviour in offspring exposed to high doses, including delayed swimming development and altered learning responses. EFSA used this study to set the group ADI for E620-E625, applying a 100-fold uncertainty factor to the no-observed-adverse-effect level. The panel found no concern for genotoxicity or carcinogenicity.
A developmental neurotoxicity study identified adverse neurobehavioural effects in offspring including delayed swimming development, diminished rearing frequency, and altered learning responses at high doses of MSG.
No indication of carcinogenicity was found in chronic studies, and glutamates did not raise concern for genotoxicity.
German BfR assessment: glutamates and neurological sensitivity
The German Federal Institute for Risk Assessment reviewed the health effects of glutamic acid and its salts used as food additives. It acknowledged reports of the MSG symptom complex in sensitive individuals but noted the evidence base for a clear dose-response relationship in the general population from food exposure remained limited. Both the BfR and EFSA concluded that the human data were not suitable for deriving a formal ADI and relied on animal data instead.
Human data on MSG sensitivity were deemed unsuitable for deriving safety values because they lacked adequate dose-response information; the ADI was therefore derived from animal studies with a full uncertainty factor applied.
Where it stands with the regulators
Who should be careful
People who report headaches, flushing, or other symptoms following meals heavy in MSG or processed savoury foods may wish to check labels for E625, E621 (monosodium glutamate), or the term 'flavour enhancer'. Children who eat large amounts of highly processed savoury food are the group most likely to exceed the intake level flagged in the EFSA assessment. Look for 'E625', 'magnesium diglutamate', or 'flavour enhancer (E625)' on the label.
The honest read
E625 is one of six glutamate additives (E620-E625) that work identically, all releasing the same glutamate ion. The 2017 EFSA re-evaluation is the most rigorous recent assessment and its finding is notable: children at high intake exceed, from additives alone, the dose associated with adverse effects in human studies. That is a regulatory concern about real-world dietary patterns, not a theoretical lab result. The practical complication is that glutamate is also abundant naturally in everyday foods, meaning the additive dose sits on top of a substantial background. EFSA's response was to recommend cutting the permitted levels in several food categories rather than to restrict the additive outright. The MSG symptom complex reported by some individuals remains scientifically contested as a reproducible dose-response phenomenon in controlled trials, but that does not resolve the exposure question EFSA raised for children.
Related additives
Common questions
Is E625 banned in the UK?
No. E625 is an approved food additive in the UK and EU. It appears on the UK FSA's list of approved additives and is authorised under assimilated EU Regulation 1333/2008. EFSA reviewed it in 2017 and recommended tightening the maximum permitted levels in some food categories, but it was not banned.
Is E625 the same as MSG?
It works in the same way. Both release glutamate, the ion that activates umami taste receptors. MSG (E621) is the sodium salt; E625 is the magnesium salt. The flavour effect on food is essentially identical. E625 is sometimes used where a manufacturer wants to reduce the sodium content contributed by MSG.
What foods contain E625?
Instant soups and noodles, stock cubes, bouillon powders, savoury crisps and snacks, ready meals, processed meat products, sauces, and seasoning blends are the most common sources. It appears on the label as 'E625', 'magnesium diglutamate', or 'flavour enhancer (E625)'.
Is E625 vegan?
Yes. Magnesium diglutamate is produced by fermentation of plant-derived sugars or by chemical synthesis. It contains no animal-derived ingredients.
Sources
- EFSA ANS Panel re-evaluation of glutamic acid (E620), sodium glutamate (E621), potassium glutamate (E622), calcium glutamate (E623), ammonium glutamate (E624) and magnesium glutamate (E625) as food additives, EFSA Journal 2017
- PMC full text of the EFSA 2017 glutamate re-evaluation
- BfR assessment of health effects of glutamic acid and glutamates as food additives
- UK FSA approved additives and E numbers
- EU Regulation (EC) No 1333/2008 on food additives (Annex II)
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