What the Evidence Actually Says About Magnesium for Sleep

Given how often magnesium is recommended for sleep, this review set out to see how much rigorous evidence actually backs it up in older adults, and found remarkably little: only three randomised controlled trials, covering 151 people across three countries, met the criteria for inclusion. Pooling them, magnesium supplementation shortened the time it took to fall asleep by about 17 minutes compared with placebo, a real and meaningful effect on paper. Total sleep time also improved, by roughly 16 minutes, though this particular result wasn't statistically significant.

The authors were candid that all three trials carried moderate to high risk of bias, and the overall quality of evidence behind these numbers was rated low to very low, meaning confidence in the exact size of the effect should stay modest. Their own conclusion was pragmatic rather than enthusiastic: the literature isn't strong enough to formally recommend magnesium, but given how cheap and widely available it is, and how mild its side-effect profile tends to be, the existing trial evidence doesn't rule it out either, a genuinely open question rather than a settled one.