Ingredient
Moderate evidenceMagnesium
Also known as: magnesium glycinate, magnesium citrate, magnesium bisglycinate
A commonly-short mineral for sleep, muscle function and recovery — if the form is right.
What it is
Magnesium is an essential mineral involved in hundreds of bodily processes, including muscle and nerve function, energy production and sleep. Many active people and those eating a typical Western diet fall a little short of the recommended intake, which is where supplementing can help.
How it works
Because magnesium is used in so many systems, correcting a shortfall can support sleep quality, muscle relaxation and recovery. The key word is correcting: if your levels are already adequate, extra magnesium does little. The form matters a lot for both absorption and stomach comfort.
Effective dose
Typical supplemental doses are around 200 to 400mg of elemental magnesium per day. Choose a well-absorbed, gentle form such as glycinate (bisglycinate) or citrate; cheap magnesium oxide is poorly absorbed and more likely to cause loose stools. Taking it in the evening suits its calming effect.
Safety and upper limit
Food magnesium is safe, but high supplemental doses, especially of poorly-absorbed forms, commonly cause diarrhoea. People with kidney problems should be cautious and seek medical advice, as they clear magnesium less effectively.
Where you find it
Standalone magnesium, ZMA products, multivitamins and sleep/recovery formulas.
Top ZMA picks
The highest-scoring products in the category where Magnesium matters most.
Frequently asked
What is the best form of magnesium?
Glycinate (bisglycinate) or citrate are well absorbed and gentle. Cheap magnesium oxide is poorly absorbed and more likely to upset the stomach.
How much magnesium should I take?
Around 200 to 400mg of elemental magnesium per day from supplements is typical. Many people take it in the evening for its calming effect.
Does magnesium help sleep?
It can, particularly if you are short of it. Correcting a shortfall supports muscle relaxation and sleep quality; topping up when already adequate does little.
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Related guides
This page is educational and not medical advice. Doses are general guidance from the published research, not a personal prescription. Before starting any supplement that could affect a medical condition or interact with medication, speak to a qualified clinician.