Mineral guide
Magnesium
Understand magnesium forms, compare daily amounts and find the differences that matter when choosing a supplement.
Compare products ↓What is magnesium?
Magnesium is an essential mineral found naturally in foods such as nuts, seeds, whole grains and green vegetables. In supplements, magnesium is bound to another substance to form compounds such as magnesium citrate, bisglycinate, oxide, malate or carbonate. The weight of that whole compound is not the same as the amount of magnesium it supplies.
What does magnesium support?
Common reasons include muscles and exercise, tiredness and fatigue, the nervous system and general wellbeing. Magnesium also appears frequently in products marketed for evening use or sleep. EU-authorised claims support normal muscle and nervous-system function, normal psychological function, normal energy-yielding metabolism and reduction of tiredness and fatigue, among several other normal physiological functions. A specific claim that magnesium improves sleep is a different matter and is not treated here as an authorised EU claim.
What happens if you don’t get enough magnesium?
Short-term low magnesium intake does not usually cause obvious symptoms because the kidneys help retain magnesium. With true deficiency, early signs can include loss of appetite, nausea, fatigue and weakness. Severe deficiency can cause numbness, tingling, muscle cramps, seizures and abnormal heart rhythms.
Symptomatic deficiency from low dietary intake alone is uncommon in otherwise healthy people. Some diseases, alcohol dependence and medicines can increase losses or reduce absorption, and magnesium status can be difficult to assess from a single measurement.
What about magnesium for sleep?
Sleep is one of the most common reasons people look for magnesium supplements. It is not an EU-authorised magnesium health claim, but it is an active area of research. A 2024 systematic review found that five of eight included studies reported improvement in at least one sleep-related measure, while the authors also noted that studies were small and varied in dose, form and design.
The research is promising enough to explain the strong consumer interest, especially in people with lower magnesium status, but it does not establish one magnesium form as the proven “best” form for sleep. For product comparison, elemental magnesium per day, tolerability and the chosen form remain more useful than a sleep-focused marketing claim alone.
Magnesium also has an authorised EU claim for normal psychological function. Supplement studies on anxiety and stress have produced encouraging signals, although systematic reviews describe the evidence as suggestive rather than conclusive. This makes psychological function a relevant benefit area without presenting magnesium as a treatment for anxiety.
Citrate, bisglycinate, oxide — does the form matter?
Magnesium is sold as different salts and complexes. The form can affect how much elemental magnesium fits into a serving, how the product is taken and how well an individual tolerates it. Marketing often ranks forms as universally “best” or “worst”, but a useful comparison needs to look at the actual dose and purpose rather than the compound name alone.
Magnesium citrate
A common supplement form. It can be a practical choice, but some people may find larger amounts loosen the bowel.
Magnesium glycinate / bisglycinate
Popular in products positioned for evening use and often marketed as gentle. The form itself does not create an authorised EU sleep claim.
Magnesium oxide
Contains a high proportion of elemental magnesium by weight and is widely used. A lower fractional absorption does not by itself tell you how much magnesium a particular product ultimately provides or whether it suits you.
Don’t compare products by the compound weight
The number that matters most on the label is the amount of magnesium supplied per daily serving — not simply the total milligrams of magnesium citrate, bisglycinate or another compound. In the EU, the nutrient reference value (NRV) for magnesium is 375 mg.
Powder, capsule or tablet — and what about tolerance?
Magnesium comes in powders, capsules and tablets, and the practical difference can matter because meaningful daily amounts may require several capsules or a larger tablet. Powders can make larger servings easier to take, while capsules may be more convenient for travel and fixed dosing.
Some supplemental magnesium forms and larger amounts can loosen the bowel. If this matters to you, compare the form, amount per serving and number of daily units rather than choosing by compound name alone. The European upper-level reference of 250 mg/day applies to readily dissociable magnesium salts from supplements and fortified foods, not magnesium naturally present in ordinary foods.
What should you compare?
Start with the amount of elemental magnesium
Check how much magnesium the recommended daily serving actually supplies and how that compares with the 375 mg NRV.
Check the magnesium form and format
Compare citrate, bisglycinate, oxide or another stated form alongside the product format and number of units in the daily serving. A premium-sounding form is not automatically better.
Match expectations to the evidence
For muscle function, nervous-system function and tiredness/fatigue, there are authorised EU claims when the conditions of use are met. For sleep or other popular uses, avoid assuming the same regulatory support.
Compare the whole product
Look at elemental magnesium per daily serving, the number of tablets or capsules, other active ingredients and label clarity — not just the front-of-pack magnesium form.
Product comparison
Compare magnesium supplements
How products are ordered: lower to higher standard labelled daily magnesium amount; equal amounts alphabetically. This is not a ranking, and a higher dose is not automatically better.
| Product | Magnesium / day | Magnesium form | Recommended serving | Magnesium / unit | Format | Vegan |
|---|---|---|---|---|---|---|
| NOW Foods Magnesium GlycinateView product ↗ | 200–400 mg | Magnesium bisglycinate (Albion™) | 2 tablets, 1–2× daily with food | 100 mg | Tablet | Vegetarian coating |
| Pharma Nord Bio-MagnesiumView product ↗ | 200–400 mg | Magnesium carbonate + hydroxide + acetate | 1–2 tablets daily | 200 mg | Tablet | Yes |
| Viridian High Potency Magnesium BisglycinateView product ↗ | 200 mg | Magnesium bisglycinate | 2 capsules | 100 mg | Plant-cellulose capsule | Yes |
| NOW Foods Magnesium 400 mgView product ↗ | 400 mg | Magnesium oxide + citrate + aspartate | 1 capsule daily | 400 mg elemental magnesium | Veg capsule | Yes |
| NOW Foods Magnesium CitrateView product ↗ | 400 mg | Magnesium citrate | 3 capsules daily, preferably divided, with food | ≈133 mg | Veg capsule | Yes |
| Solgar Magnesium CitrateView product ↗ | 400 mg | Magnesium citrate | 2 tablets daily, preferably with a meal | 200 mg | Tablet | Yes |
EU health claim details
Authorised wording, conditions of use and regulatory sources for magnesium.
EU-authorised magnesium claims (10)
● Magnesium contributes to a reduction of tiredness and fatigue.Tiredness & fatigue · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- SRC-432-2012
● Magnesium contributes to electrolyte balance.Electrolyte balance · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium contributes to normal energy-yielding metabolism.Energy metabolism · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium contributes to normal functioning of the nervous system.Nervous system · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium contributes to normal muscle function.Muscle function · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216; 2010;8(10):1807
- EU legal source
- SRC-432-2012
● Magnesium contributes to normal protein synthesis.Protein synthesis · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium contributes to normal psychological function.Psychological function · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- SRC-432-2012
● Magnesium contributes to the maintenance of normal bones.Bones · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium contributes to the maintenance of normal teeth.Teeth · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
● Magnesium has a role in the process of cell division.Cell division · General population
- Claim type
- Article 13 — Function
- Assessment status
- Authorised
- Condition of use
- Food must be at least a source of magnesium.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- SRC-432-2012
Claim use requirements
For claims requiring the food to be a source of magnesium, the general EU significant-amount reference levels based on the 375 mg NRV are:
28.125 mg / 100 ml for beverages
56.25 mg per portion if the package contains only one portionThe finished product and recommended serving must meet the applicable conditions before a claim is used commercially.
Sources
Other assessed health claims (13)
These entries are not authorised claims. Assessment status is retained from the existing database.
● An adequate magnesium intake can support to maintain normal blood pressureBlood pressure ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the scientific evidence assessed was insufficient to substantiate the claimed effect.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Magnesium contributes to meeting the increased requirement for magnesium in pregnant women, so it could help the normal course of pregnancy and delivery and birth of a healthy baby.Pregnancy ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Magnesium contributes to the maintenance of hormonal health.Hormonal health ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not sufficiently defined to be assessed and therefore could not be substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Magnesium has antioxidative properties. It prolongs the ageing process.Oxidative stress ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Magnesium is necessary for normal blood clottingBlood clotting ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not substantiated.
- EFSA / scientific assessment
- EFSA Journal 2009;7(9):1216
- EU legal source
- —
● Magnesium maintains healthy immune systemImmune system ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Regulates blood pressure.Blood pressure ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the scientific evidence assessed was insufficient to substantiate the claimed effect.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Regulates sugar balance.Blood glucose ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because the claimed effect was not substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Le Magnésium vous aide à lutter contre les petits stress quotidiens.Mental stress ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because on the basis of the scientific evidence assessed, this claimed effect for this food has not been substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Essentiel à la régulation de la pression artérielle.Blood pressure ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because on the basis of the scientific evidence assessed, the evidence provided is insufficient to substantiate this claimed effect for this food.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Le magnésium est essentiel au métabolisme des lipides.Fat metabolism ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because on the basis of the scientific evidence assessed, this claimed effect for this food has not been substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Permet à l'organisme de s'adapter au stress.Mental stress ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because on the basis of the scientific evidence assessed, this claimed effect for this food has not been substantiated.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —
● Helps to maintain acid-base balance. Helps to decrease dietary acid load. Helps in case of occasional gastric acidity. Contributes to decrease gastric acidity.Gastric acidity ·
- Claim type
- Article 13 — Function
- Assessment status
- Non-authorised
- Condition of use
- —
- Additional statement / restriction
- Non-compliance with the Regulation because on the basis of the scientific evidence assessed, this claimed effect for this food is not a beneficial physiological effect as required by the Regulation.
- EFSA / scientific assessment
- EFSA Journal 2010;8(10):1807
- EU legal source
- —