Weak evidence · Vitamins & minerals
Magnesium
Muscle and nerve function when deficient
Weak evidence
Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
Magnesium is involved in hundreds of enzyme reactions in your body. For sleep the evidence is contradictory: in observational research better magnesium status goes with better sleep, but randomised studies show no consistent effect of supplements. For cramps, a 2020 Cochrane review found that magnesium probably gives no clinically meaningful cramp reduction.
- Dosage
- As per the label
- Timing
- With a meal
- Approx. price
- €5–12 per month
Watch out
The form determines absorption and the chance of a laxative effect; go by the elemental magnesium content, not the total weight of the salt. Too much can cause diarrhoea.
Frequently asked questions about supplements
How much Magnesium per day?
As per the label
When should you take Magnesium?
With a meal
Does Magnesium really work?
Weak evidence. Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
What does Magnesium cost?
€5–12 per month
Basics first, then the tub
Supplements are called supplements because they add to something. Sleep, a protein intake that hits your protein calculator , a programme where you lift progressively heavier and enough food together do a hundred times more than the best-researched item on this list. Once those are in place, creatine, caffeine and vitamin D in winter are the three you can spend money on with a clear conscience — for less than ten euros a month combined.
Sources
- Garrison SR et al. (2020). Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev CD009402. (Cochrane review)
- The role of magnesium in sleep health: a systematic review of available literature (2022). (systematic review)
More supplements in this category
Last updated: October 2026
This page summarises scientific research and is not medical advice. If you take medication, are pregnant or have a liver, kidney or thyroid condition, discuss supplements with your doctor or pharmacist — even the innocent-looking ones.
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