Forms of magnesium: oxide, citrate, bisglycinate… how to read the label

This guide is for information only; it does not replace advice from a doctor, pharmacist or midwife.

A supplement does not contain magnesium on its own: it contains a magnesium salt or compound (oxide, citrate, bisglycinate…), that is, magnesium bound to another molecule. The weight of that salt and the amount of magnesium it provides are therefore two different numbers. One figure given by EFSA: magnesium citrate malate contains 12 to 15% magnesium [7].

German products follow the EU rules on food supplements. Directive 2002/46/EC requires the label to state, in figures, the amount of each nutrient present in the product — for magnesium, in milligrams — per portion recommended by the manufacturer for daily consumption (Article 8; in the German text, “pro empfohlener Tagesdosis”); on German packs, look for the word “Tagesdosis” [2]. This is the amount of magnesium itself, sometimes called “elemental” magnesium. The form used appears in the list of ingredients (“Zutaten”), which is mandatory on foods [3].

The directive also requires vitamins and minerals to be expressed as a percentage of the reference values (Article 8(3)): this is the “% NRV” on German packs. For magnesium, 100% corresponds to 375 mg for an adult (Regulation (EU) No 1169/2011, Annex XIII) [3]. To compare two products, compare the “Magnesium” line for the daily portion, not the total weight of the tablet or capsule.

In the EU, a food supplement may only use the forms of magnesium listed in Annex II of Directive 2002/46/EC (Article 4) [2]. The list includes magnesium oxide (Magnesiumoxid), carbonate (Magnesiumcarbonat), hydroxide, chloride, sulphate, magnesium salts of citric acid, i.e. citrates (Magnesiumsalze der Zitronensäure), citrate malate, bisglycinate (Magnesiumbisglycinat), lactate, gluconate, malate, taurate and L-threonate. The German names in brackets come from the German version of the directive and help you spot the form in the list of ingredients.

None of the European opinions consulted for this guide ranks these forms from “best” to “worst”. When EFSA assessed magnesium citrate malate in 2018, it concluded that its magnesium is bioavailable, but that the extent of its bioavailability, per se or compared with other magnesium sources, could not be established because the studies provided lacked an appropriate comparator [7]. This guide therefore does not repeat the absorption or tolerance rankings found online.

If you are hesitating between two forms for a health reason (digestion, an illness, ongoing treatment), ask your pharmacist or doctor.

The format alone does not tell you how much magnesium you get: whatever the format, read the “Magnesium” line and the daily portion. The SCF notes that the dosage form (solution, capsules, tablets…) may play a role in digestive tolerance [5]; none of the official sources consulted ranks these formats against each other.

Food supplements do not have to show the nutrition table used on other foods (energy, salt…): Regulation (EU) No 1169/2011 exempts them (Article 29) [3]. If you have been told to limit salt or sodium, read the list of ingredients, including on an effervescent tablet, and show it to your pharmacist if in doubt.

To see the products, go to the magnesium aisle or the health and supplements aisle.

For total intake, food included, EFSA set Adequate Intakes in 2015 of 350 mg per day for men and 300 mg per day for women. It could not derive an Average Requirement; its values are based on intakes observed in healthy populations in the EU. For pregnancy and breastfeeding, it keeps the same value as for other women, as there is no evidence of an increased need [4].

For children, EFSA sets 80 mg per day from 7 to 11 months, 170 mg from 1 to under 3 years, 230 mg from 3 to under 10 years, then, from 10 to under 18 years, 300 mg for boys and 250 mg for girls [4]. These values describe the diet: they do not say how much of a supplement to take.

The safety limit is a different benchmark. Set in 2001 by the Scientific Committee on Food (SCF), EFSA's predecessor, and still used by EFSA [5][6][7], it is 250 mg per day of magnesium from readily dissociable salts (for example chloride, sulphate, aspartate, lactate) and compounds such as the oxide, in food supplements, water or added to foods and beverages. It does not include magnesium naturally present in foods. It applies to adults, including during pregnancy and breastfeeding, and to children from 4 years; no limit could be set for ages 1 to 3, for lack of data [5].

The effect used to set this limit is diarrhoea: magnesium can have an “osmotic” effect in the gut that loosens stools. According to the SCF, this diarrhoea is reversible within one to two days and is not a significant health risk in people whose kidneys work normally; it also notes that the osmotic effect of magnesium sulphate is greater than that of other salts [5].

If a product's daily portion exceeds this benchmark, if you combine several products that contain magnesium (for example multivitamins or a calcium-magnesium combination), or if your stools become loose, talk to your pharmacist or doctor. We cannot set a dose for you.

Regulation (EU) No 432/2012 permits ten health claims for magnesium. Here is the official English text, word for word [1]: “Magnesium contributes to a reduction of tiredness and fatigue”; “Magnesium contributes to electrolyte balance”; “Magnesium contributes to normal energy-yielding metabolism”; “Magnesium contributes to normal functioning of the nervous system”; “Magnesium contributes to normal muscle function”; “Magnesium contributes to normal protein synthesis”; “Magnesium contributes to normal psychological function”; “Magnesium contributes to the maintenance of normal bones”; “Magnesium contributes to the maintenance of normal teeth”; “Magnesium has a role in the process of cell division”.

Each “may be used only for food which is at least a source of magnesium”, as defined in Regulation (EC) No 1924/2006 [1]. These sentences describe the role of the nutrient, whatever its form: none of them refers to the oxide, the citrate or the bisglycinate in particular, and none promises what a given product will do for a given person.

Ask for advice before taking a magnesium supplement in the following cases. Kidney disease: the SCF lists severely impaired kidney function among the risk factors for too much magnesium in the blood [5]. Ongoing treatment: the SCF mentions interactions with certain medicines, including antibiotics, and points out that most diuretics can disturb the kidney's ability to retain magnesium [5]; your pharmacist will tell you what to do. Pregnancy, breastfeeding, children, repeated diarrhoea: here too, ask a doctor, pharmacist or midwife.

Finally, a food supplement does not replace a varied diet — this is even a mandatory statement on its label (Directive 2002/46/EC, Article 6) [2] — nor the advice of a healthcare professional.

All consulted on 07/11/2026.

1. European Union — Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, Annex, consolidated version of 20/08/2025 (https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:02012R0432-20250820)

2. European Union — Directive 2002/46/EC of 10 June 2002 on food supplements, Articles 4, 6 and 8, Annexes I and II, consolidated version of 26/11/2025 (https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:02002L0046-20251126)

3. European Union — Regulation (EU) No 1169/2011 of 25 October 2011 on the provision of food information to consumers, Articles 9, 29, 30 and 53, Annex XIII, consolidated version of 01/04/2025 (https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:02011R1169-20250401)

4. EFSA NDA Panel — “Scientific Opinion on Dietary Reference Values for magnesium”, EFSA Journal 2015;13(7):4186, abstract (https://doi.org/10.2903/j.efsa.2015.4186)

5. Scientific Committee on Food (SCF) — “Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Magnesium”, 26 September 2001, published in EFSA, “Tolerable Upper Intake Levels for Vitamins and Minerals”, 2006 (https://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf)

6. EFSA — “Overview on Tolerable Upper Intake Levels as derived by the Scientific Committee on Food (SCF) and the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)”, version 11, August 2025 (https://www.efsa.europa.eu/sites/default/files/assets/UL_Summary_tables.pdf)

7. EFSA NDA Panel — “Magnesium citrate malate as a source of magnesium added for nutritional purposes to food supplements”, EFSA Journal 2018;16(12):5484 (https://doi.org/10.2903/j.efsa.2018.5484)