Magnesium forms compared: bisglycinate, citrate & co.
Futures Nutrition Editorial Team · 10 August 2026
Magnesium forms compared: bisglycinate, citrate & co.
10 August 2026
The front of the pack says "magnesium" – the back then says bisglycinate, citrate, oxide or malate. Those words are not marketing but chemistry: in food supplements magnesium never occurs on its own, it is always bound to a partner. Which partner that is decides two very practical things – how much magnesium a tablet actually contains, and how easy it is to swallow.
This article sets out the differences factually and shows how to read a label correctly in thirty seconds.
Magnesium contributes to the reduction of tiredness and fatigue. Magnesium contributes to normal muscle function. Magnesium contributes to the normal functioning of the nervous system.
Why magnesium always has a "form"
Pure magnesium is a metal and in that shape the body cannot use it. In food supplements it therefore appears as a magnesium compound: bound to an acid or an amino acid. That bond is what people colloquially call the "form".
Two groups are distinguished:
- Organic compounds – bound to an organic acid or an amino acid. These include bisglycinate, citrate, malate and lactate.
- Inorganic compounds – bound to a mineral partner. These include oxide, carbonate and sulphate.
Elemental content: the number that matters
This is where the most common shopping mistake arises. "500 mg magnesium citrate" and "500 mg magnesium" are not the same thing. The compound weighs more than the magnesium inside it – the partner is on the scales too.
The share of actual magnesium is called the elemental content, and it differs markedly between forms:
| Form | Elemental content (approx.) | Group |
|---|---|---|
| Magnesium oxide | 60 % | inorganic |
| Magnesium carbonate | 28 % | inorganic |
| Magnesium citrate | 16 % | organic |
| Magnesium malate | 15 % | organic |
| Magnesium bisglycinate | 14 % | organic |
An example: 1,000 mg of magnesium oxide contains around 600 mg of magnesium, whereas 1,000 mg of bisglycinate contains only about 140 mg. Anyone who looks only at the big number on the front is comparing apples with pears.
Reading a label in thirty seconds: in the nutrition table, find the line for "magnesium" and the accompanying NRV percentage (Nutrient Reference Value). That figure always refers to elemental magnesium – regardless of the form. Everything else on the front of the pack is secondary.
The forms in detail
Magnesium bisglycinate
Here magnesium is bound to two molecules of the amino acid glycine – hence "bis"-glycinate. This compound is also referred to as magnesium chelate. At around 14 %, the elemental content is low, which is why products in this form usually deliver less magnesium per tablet than oxide preparations, and are correspondingly larger or more numerous.
In our range you will find this form as magnesium bisglycinate 150 mg – 150 mg of elemental magnesium per tablet, which corresponds to 40 % of the Nutrient Reference Value.
Magnesium citrate
Magnesium bound to citric acid – the same molecule that gives citrus fruit its taste. Citrate is the most widespread organic form in Europe and is especially common in powders because it dissolves well in water.
Magnesium oxide
The compound with the highest elemental content: around 60 % of the weight is magnesium. Oxide preparations can therefore make do with small tablets. It is the classic form in low-priced products.
Magnesium malate
Magnesium bound to malic acid (malate), which occurs naturally in apples. The elemental content is around 15 %.
What magnesium does in the body
The authorised claims for magnesium are laid down uniformly across the EU (Regulation (EU) No 432/2012). The following is permitted:
- Magnesium contributes to the reduction of tiredness and fatigue.
- Magnesium contributes to normal muscle function.
- Magnesium contributes to the normal functioning of the nervous system.
- Magnesium contributes to electrolyte balance.
- Magnesium contributes to normal energy-yielding metabolism.
- Magnesium contributes to the maintenance of normal bones and teeth.
These claims apply to magnesium as a nutrient – irrespective of the compound it comes in. No form is therefore "more effective" than another; they differ in elemental content, solubility and tolerability.
How much magnesium per day?
The Nutrient Reference Value (NRV) for magnesium in the EU is 375 mg per day. This figure appears as the reference quantity on every nutrition table and is the basis for the percentage figures.
Part of it comes from the diet: wholegrain products, nuts, pulses, green vegetables and mineral-rich water are good sources. Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.
What to look for when buying
- Elemental content rather than compound weight. Compare the "magnesium" line in mg, not the number on the front of the pack.
- Mind the daily portion. Some figures refer to two or three tablets, not to one.
- Check the declaration. The pack must state which compound is used.
- Do not exceed the recommended daily dose. Larger amounts of magnesium can have a laxative effect – this notice is customary on magnesium-containing products.
Frequently asked questions
Is a more expensive form automatically better?
No. The price per tablet says little; what matters is the price per milligram of elemental magnesium. Always convert to that figure when comparing.
Why do bisglycinate products often contain less magnesium per tablet?
Because the glycine share is on the scales too. At around 14 % elemental content, a tablet with 150 mg of magnesium already needs a good gram of bisglycinate – physically, not much more will fit into a tablet that can still be swallowed.
Can I take magnesium together with other minerals?
That is common practice; many combination preparations contain several minerals. Follow the information on the particular pack and do not exceed the recommended daily dose.
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