Magnesium bisglycinate: what it is, and what may lawfully be said about it
A chelated form with a reputation for gentleness. What the EU register authorises applies to magnesium, not to bisglycinate — and that distinction changes everything.
What bisglycinate actually is
Magnesium is never consumed on its own: it is a metal, always bound to something else. That pairing is called a salt, or in some cases a chelate. Magnesium oxide pairs magnesium with oxygen, citrate with citric acid, bisglycinate with two molecules of glycine — an amino acid.
The difference is not cosmetic. It determines two measurable things: elemental magnesium content, and how the salt behaves in the gut.
Content first. A gram of magnesium oxide holds roughly 60 % elemental magnesium; a gram of bisglycinate holds about 14 %. In other words, a capsule advertising “300 mg of magnesium bisglycinate” does not deliver 300 mg of magnesium, but around 42 mg. That is the first thing to check on a label, and the most frequently glossed over.
Digestive behaviour second. Bisglycinate is a chelate: the magnesium is wrapped by glycine, which makes it less reactive in the intestine. Hence its reputation for tolerance — highly ionic forms such as oxide or chloride have a marked osmotic effect, familiar to anyone who has taken magnesium on an empty stomach.
What the EU register authorises
Here is the point most brands deliberately keep vague. The EU register of health claims authorises four claims for magnesium. They are reproduced below, word for word.
Those claims apply to magnesium. Not to bisglycinate, not to citrate, not to malate. No particular form holds a claim of its own, because none has been the subject of an authorised application on that basis.
The direct consequence: a brand writing “bisglycinate reduces fatigue” steps outside the framework. It attributes to a form what is authorised for a nutrient. The lawful wording is the register’s, and the product must reach the required dose to use it.
Authorised claims — register wording
- « Magnesium contributes to the reduction of tiredness and fatigue. »
- Magnésium · ≥ 15 % des VNR (56,25 mg) par portion.
- « Magnesium contributes to normal functioning of the nervous system and to normal psychological function. »
- Magnésium · ≥ 15 % des VNR (56,25 mg) par portion.
- « Magnesium contributes to normal muscle function. »
- Magnésium · ≥ 15 % des VNR (56,25 mg) par portion.
- « Magnesium contributes to electrolyte balance. »
- Magnésium · ≥ 15 % des VNR (56,25 mg) par portion.
Note · No authorised claim concerns sleep. Magnesium sold as a “natural sleeping aid” goes beyond what the register permits, whatever its form.
The 15 % threshold, and why it decides everything
To carry a claim, a product must supply at least 15 % of the nutrient reference value per portion. For magnesium the NRV is 375 mg, so the threshold is 56.25 mg of elemental magnesium per portion.
That figure is the most useful filter on the shelf. A supplement delivering 30 mg of elemental magnesium may claim nothing at all, even with “200 mg of bisglycinate” printed large on the box. The maths is simple: salt content × advertised weight.
It is also why comparing prices per gram of powder is meaningless. The only meaningful comparison is price per milligram of elemental magnesium, at equal tolerance.
| Form | Elemental magnesium | To reach 56.25 mg |
|---|---|---|
| Oxide | ~60 % | ~94 mg of salt |
| Citrate | ~16 % | ~350 mg of salt |
| Bisglycinate | ~14 % | ~400 mg of salt |
| Malate | ~15 % | ~375 mg of salt |
What we don’t know
Bisglycinate’s absorption advantage is often presented as settled. It is not, at the level of proof a European claim demands: the available work involves small samples, heterogeneous protocols and varying endpoints — serum, urinary and erythrocyte magnesium do not tell the same story.
Digestive tolerance is better established. That is a legitimate reason to prefer this form, and it is a comfort argument — not a health claim. So that is how we write it, and not otherwise.
Frequently asked
Is bisglycinate better than citrate?
For digestive tolerance, it is generally better handled. For the claim, the question is moot: the EU register does not distinguish forms. What matters in regulatory terms is the amount of elemental magnesium per portion, not the salt carrying it.
How much magnesium per day?
The European nutrient reference value is 375 mg a day, dietary intake included. A supplement fills a gap; it does not replace food. Beyond ordinary intakes, seek advice from a healthcare professional, particularly with kidney impairment.
Does magnesium help you sleep?
No sleep claim is authorised for magnesium. Two authorised claims link it to normal nervous-system function and normal psychological function, which is not the same thing. For falling asleep, the only authorised claim concerns melatonin, from 1 mg.
Morning or evening?
No European condition of use sets a time for magnesium — unlike melatonin, whose claim requires intake shortly before bedtime. Timing is therefore a matter of digestive comfort and consistency, not regulation.
The products concerned
Sources
Only regulatory texts and public registers, checkable by anyone. No bibliographic reference is cited without verification: on a health topic, a false source costs more than none.
- Règlement (UE) n° 432/2012
Establishes the list of permitted claims other than disease-risk-reduction ones, with their conditions of use.
- Commission européenne — EU Register of nutrition and health claims
Searchable database of every authorised and rejected claim. The reference that lets anyone check, word for word, what a product may state.
- Règlement (UE) n° 1169/2011
Sets the reference intakes (NRV) used to express a percentage on a label, and prohibits misleading statements about a food’s properties.
- Directive 2002/46/CE
Governs the composition and labelling of food supplements: permitted vitamins and minerals, mandatory statements, warnings.
Our method
No health claim is written by us: every such sentence is taken word for word from the EU register. An active with no authorised claim is presented with none — never with a softened wording.
Food supplements are not a substitute for a varied, balanced diet or a healthy lifestyle. This page is informational and is not medical advice. If you are on medication, pregnant or breastfeeding, seek advice from a healthcare professional.
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