Is there a magnesium dose for stress?

By Tom Francis·Updated 2026-09-03·2 sources·Editorial policy

What is authorised and what is not

Magnesium contributes to normal psychological function and to the normal functioning of the nervous system, at a serving providing at least 15 percent of the 375mg reference value. Those are the nearest authorised claims to this question.

Neither is a stress claim. Contributing to normal psychological function means the nutrient plays its part when intake is adequate, not that supplementing above adequacy reduces stress. There is no authorised claim for stress, anxiety or relaxation for magnesium at any dose.

Why there is no dose to give

A dose can only be given against a claim, because the claim specifies the condition of use. The 250mg omega 3 figure exists because the heart claim names it. The 15 percent NRV threshold exists because the magnesium claims name it.

With no stress claim there is no condition of use, so any figure quoted for stress relief comes from a manufacturer rather than a regulator. Futuro Labs Magnesium Glycinate provides 300mg of elemental magnesium at 80 percent NRV for 22p a day, which covers the authorised claims comfortably and is not offered for stress.

What the question usually sits underneath

Often a period of poor sleep, high workload and too much caffeine, which is a common situation for a club player training late and working early. None of that is a nutrient problem and none of it is fixed from a shelf.

Anything persistent, worsening, or affecting daily life belongs with a GP rather than a supplement page. That is the useful answer to this query and it is not a supplement one.

The full version

• Magnesium and tiredness in rugbyThe claim that comes closest, and when tiredness becomes medical.
• Magnesium and sleep after evening rugby trainingWhy there is no sleep claim and what actually keeps players awake.

Questions players ask

Sources

• EFSA register of nutrition and health claims
• Food supplements guidance, gov.uk