Magnesium
An essential mineral found in seeds, nuts, beans and leafy greens. The supplement evidence depends on the question: correcting an inadequate intake, improving sleep and preventing migraine are different uses.
What have studies measured?
Sleep, migraine prevention and night-time cramps have different results and different levels of confidence.
Some positive findings; results across trials are inconsistent.
Low–very low certaintyLimited evidence for reducing frequency in diagnosed migraine.
Possible benefitNight-time muscle crampsOlder adults are unlikely to gain a meaningful benefit.
Moderate certainty
Read the research
Magnesium supplementation and sleep
Lopresti, Smith & Drummond. Twelve sleep trials; low to very low certainty. Differences between studies make a single pooled answer inappropriate.
Open review summarySearch date, scope and interpretationMagnesium bisglycinate in adults reporting poor sleep
Schuster et al. A placebo-controlled experiment with a small improvement in a reported insomnia score.
Open trial breakdownPopulation, duration, result and limitationsMagnesium for skeletal muscle cramps
For older adults with usual night-time cramps, a clinically meaningful benefit is unlikely.
Read the Cochrane summarySources & further reading
Clinical papers, nutrition references and manufacturer labels are identified separately.