Ingredients

Magnesium

Magnesium supplements come in many chemical forms. Labels declare the amount of magnesium itself, not the weight of the salt. EFSA's upper level applies only to supplemental magnesium, not to magnesium from ordinary food.

At a glance

Forms permitted in food supplements

Listed in Directive 2002/46/EC Annex II — including magnesium acetate, carbonate, chloride, citrate, gluconate, glycerophosphate, hydroxide, lactate, oxide, sulphate and bisglycinate; consult the current consolidated Annex for the full list

Nutrient reference value (labelling)

375 mg per day (Regulation (EU) No 1169/2011, Annex XIII)

Upper level for supplemental magnesium

250 mg/day of readily dissociable magnesium salts and compounds such as magnesium oxide, for adults and children from 4 years (Scientific Committee on Food, adopted by EFSA)

Cosmetic INCI names

e.g. Magnesium Sulfate, Magnesium Chloride, Magnesium Ascorbyl Phosphate, Magnesium Aluminum Silicate

Forms and labelling

Magnesium cannot be used on its own, so supplements contain it as a salt or chelate. The forms differ in their magnesium content by weight: magnesium oxide is about 60% magnesium, while organic salts such as citrate or bisglycinate contain much less. To hit the same declared amount, a product with an organic salt therefore needs a larger quantity of the compound. Labels must declare the quantity of magnesium per daily portion. In practice this is the elemental amount, often alongside the percentage of the 375 mg reference intake. Manufacturers make claims about differences in absorption between forms. The evidence on how much these differences matter for typical users is mixed, and such claims are not among the authorised health claims.

The upper level

The tolerable upper intake level of 250 mg per day applies to magnesium from supplements, water and fortified foods in readily dissociable forms. It does not include magnesium naturally present in ordinary foods. It was set on the basis of mild, transient diarrhoea, the most common effect of excess supplemental magnesium. There is no harmonised EU maximum amount per product, and national limits vary.

Authorised health claims

Authorised claims for magnesium in the EU Register include that it contributes to a reduction of tiredness and fatigue, to electrolyte balance, to normal energy-yielding metabolism, to normal functioning of the nervous system, to normal muscle function, to normal protein synthesis, to normal psychological function, and to the maintenance of normal bones and teeth. It also has a role in the process of cell division. The claims may be used only when the product contains at least a significant amount of magnesium as defined in the conditions of use. Claims about sleep, cramps or stress relief in disease terms are not authorised.

Safety considerations

Supplemental magnesium is generally well tolerated within the upper level. Higher amounts commonly cause loose stools, and magnesium salts are also used as laxatives in medicinal products. People with impaired kidney function can accumulate magnesium and should take supplements only on medical advice. Magnesium can reduce the absorption of some medicines, including certain antibiotics (tetracyclines, fluoroquinolones) and bisphosphonates, so a pharmacist may advise separating doses. This page does not give dosing advice.

In cosmetics

Magnesium salts also appear in cosmetics: magnesium sulfate in bath salts, magnesium chloride in "magnesium oil" sprays and flakes, and magnesium aluminium silicate as a thickener. In cosmetics these are regulated under Regulation (EC) No 1223/2009. Topical magnesium products are not food supplements and cannot carry nutritional health claims.

Frequently asked questions

How much magnesium is in magnesium oxide or citrate?

Magnesium oxide is roughly 60% magnesium by weight; organic salts such as citrate and bisglycinate contain considerably less. The label must state the amount of magnesium itself per daily portion.

What is the upper limit for magnesium supplements?

EFSA applies a tolerable upper intake level of 250 mg per day for supplemental magnesium (readily dissociable salts and compounds such as magnesium oxide) for adults and children from 4 years. Magnesium naturally present in food is not included.

Which magnesium forms are allowed in EU food supplements?

Those listed in Annex II of Directive 2002/46/EC, including oxide, citrate, carbonate, chloride, gluconate, lactate, glycerophosphate, sulphate and bisglycinate. The current consolidated text gives the full list.

What claims can magnesium supplements make in the EU?

Only claims authorised in the EU Register, such as "magnesium contributes to a reduction of tiredness and fatigue" or "to normal muscle function", under the stated conditions of use.

Last reviewed: October 2026.