What is the evidence for magnesium glycinate supplements in middle aged men?

What the evidence says

Magnesium glycinate is a form of magnesium bound to the amino acid glycine, often marketed as being gentler on the stomach than other forms like magnesium oxide. Most research on magnesium supplements as a whole has not used this specific form, so directly proven benefits are limited.

For sleep, one placebo-controlled trial specifically tested magnesium bisglycinate in adults with poor sleep and found a small improvement in insomnia symptoms after four weeks, though the effect size was small and other trials of magnesium in general for sleep, mostly in older adults, showed low-quality, inconsistent results.

For anxiety and stress, reviews of the available trials found mixed results: some studies show improvement, others show none, and the overall quality of evidence is weak, meaning no confident conclusion can be drawn about whether magnesium supplements reduce anxiety in general.

For muscle cramps, a Cochrane systematic review, the highest-quality type of evidence review, concluded that magnesium supplements are unlikely to meaningfully reduce cramp frequency in older adults, and can cause mild stomach upset in some people.

Claims that magnesium raises testosterone or improves muscle strength in men come from small early studies, often in athletes or older men, that hint at a possible link but are too limited in size and design to prove a real effect. Larger, well-designed trials are needed before this can be considered established.