Citrate or bisglycinate: what actually differs
Two forms, two digestive behaviours, one and the same authorised claim. How to choose on criteria that actually exist.
A real difference, but not the one being sold
Magnesium citrate is an organic salt: magnesium bound to citric acid. Bisglycinate is a chelate: magnesium wrapped by two glycine molecules. Both deliver comparable elemental magnesium, around 14 to 16 % of weight.
Their difference lies in what happens in the intestine. Citrate stays more ionic and more osmotically active — it draws water into the intestinal lumen. That is precisely why magnesium citrate is used as a laxative at high doses. Bisglycinate, better wrapped, produces markedly less of that effect.
For someone with a sensitive gut, that difference is decisive and shows up within the first week. For someone else, it is invisible.
On claims: strictly identical
The four authorised magnesium claims apply to either one, as soon as the portion reaches 56.25 mg of elemental magnesium. Neither form unlocks an extra claim.
Any communication implying that one form “works better” on fatigue, stress or muscles adds a promise where the framework authorises none.
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.
How to choose, concretely
Three questions suffice, in this order.
Is your gut sensitive? If so, bisglycinate avoids the discomfort that is the leading cause of abandoning a course. If not, the question does not arise.
What elemental content is stated? If the label only gives the salt weight without the elemental magnesium, that is a signal in itself. A brand that omits the figure rarely benefits from you calculating it.
What is the price per elemental milligram? At equivalent tolerance, that is the only rational trade-off. Citrate is generally cheaper at equal content, because it costs less to produce.
Note · One point independent of any form: magnesium interacts with certain treatments, notably some antibiotics and diuretics. If you are on medication, your pharmacist’s advice outranks any comparison table.
Frequently asked
Can you alternate between them?
Nothing prevents it, but the benefit is limited: the claims are identical and magnesium is not usefully stored. Consistency of intake matters more than alternating forms.
Does citrate always cause diarrhoea?
No. The effect depends on dose and individual sensitivity. It becomes common at high doses taken at once, and eases considerably when split across meals.
What about marine magnesium?
“Marine magnesium” is usually an oxide-dominant blend — the richest in elemental magnesium but also the most osmotically active. Marine origin confers no additional claim.
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.
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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