Magnesium for sleep and recovery

What magnesium does

Magnesium is a cofactor in more than 300 enzyme systems, including those behind protein synthesis, energy production and nerve and muscle function.¹ Good sources are everyday foods: nuts and seeds, leafy greens, legumes and whole grains.¹

Do athletes need more?

Probably a little. A review by researchers at the US Department of Agriculture found that strenuous exercise increases magnesium lost in urine and sweat, which may raise requirements by 10 to 20%. Athletes in weight-class sports, who restrict food, look especially vulnerable.²

The same review is clear about the limit: correcting a shortfall can help performance, but supplementing people who already get enough has not been shown to enhance it.²

Magnesium and sleep

This is where claims run ahead of evidence. A 2021 systematic review found only three randomised trials of oral magnesium for sleep, all in older adults with sleep complaints, 151 people in total. Pooled, people fell asleep about 17 minutes faster than with placebo; total sleep time did not change significantly. The authors rated the evidence low to very low quality and said it was not strong enough to make recommendations.³

Which form

Forms that dissolve well in liquid are absorbed more completely. According to the NIH Office of Dietary Supplements, the aspartate, citrate, lactate and chloride forms tend to have higher bioavailability than magnesium oxide and magnesium sulfate.¹

Glycinate is popular for evening use, but there is little direct research comparing it with other forms for sleep. Malate, the form in SOLACE and CALM, is magnesium bound to malic acid; it is also less studied head to head. Treat confident rankings of forms with caution.

How much is too much

For adults, the upper limit for magnesium from supplements and medicines is 350 mg a day; magnesium from food does not count towards it.¹ Too much from supplements commonly causes diarrhoea. If you take medication or have kidney problems, speak to a doctor first.

In practice

• Food first. Seeds, nuts, beans and greens most days.
• Supplement a gap, not a hope. Especially if you sweat heavily or restrict food.
• Evening is a natural time. It fits a wind-down routine, alongside L-theanine and the habits in the evening window.

A note on the studies above: they tested set amounts of a single ingredient over weeks. A shot is not a study protocol, and we do not claim that SOLACE or CALM reproduces these results.