Why the form changes how you read the product
A “magnesium 300 mg” can mean two very different things: 300 mg of the salt (the whole compound) or 300 mg of elemental magnesium (the ion). European labelling requires the elemental intake to be declared, but trade names and capsule weights keep the confusion alive. First practitioner reflex: find the elemental content per dose, then compare it with the NRV of 375 mg (Regulation (EU) No 1169/2011).
The three families of forms
Chelated forms (bisglycinate, taurate)
Here the magnesium is bound to an amino acid: two glycines for bisglycinate, taurine for taurate. These complexes are stable and soluble; their elemental content is moderate (10 to 14 % for bisglycinate), which often means several doses to reach the target intakes. Some raw materials are standardised under a brand name (for example TRAACS®, Albion®), which is stated on the product sheet.
Organic salts (citrate, malate, glycerophosphate)
Salts of organic acids, heavily represented in the catalogue. Citrate (≈ 16 % elemental) is highly water-soluble; malate (≈ 15 %) is similar on this criterion; glycerophosphate (≈ 12 %) is fat-soluble and also supplies phosphorus. Their high solubility makes them easy to formulate into powders and drinks.
Mineral forms (oxide, hydroxide, marine magnesium)
Maximum elemental content (oxide assays at around 60 %), and therefore high doses in a small capsule volume: that is their main advantage. Their solubility in water, on the other hand, is limited. “Marine magnesium” is a mixture of salts extracted from seawater, mostly oxide and hydroxide, sometimes enriched with other minerals from the marine matrix.
Speciality forms
L-threonate (≈ 8 % elemental) and acetyl-taurinate are the subject of their own literature; they are more expensive forms, positioned by manufacturers for targeted uses. Their low elemental content means you have to read the actual dose per serving carefully.
Common combinations
Vitamin B6 and taurine often accompany magnesium in the formulas in the catalogue. Vitamin B6 has its own EU claims (notably “vitamin B6 contributes to reducing fatigue”); the combination is therefore also a labelling strategy. The exact composition and the doses of each cofactor appear on the product sheets.
How to choose, in practice
Three factual questions are enough to sort the catalogue: what dose of elemental magnesium per serving and per day? Which form (and therefore which trade-off between content, solubility and capsule volume)? Which excipients and what monthly budget? The comparison table below summarises the orders of magnitude, and each product sheet in the catalogue details the exact composition, the doses observed and the practitioner price.
