MagnesiumBisglycinate / citrate / oxide · 4 claims

The meta-analysis on insomnia in older adults found three randomised trials, 151 participants, across three countries. Sleep onset latency was 17.36 minutes shorter than placebo (95% CI −27.27 to −7.44, p=0.0006). Total sleep time improved by 16 minutes and was not statistically significant.

The reviewers stated that all trials were at moderate-to-high risk of bias, evidence was low to very low quality, and that “the quality of literature is substandard for physicians to make well-informed recommendations.” Their practical conclusion was essentially that magnesium is cheap and harmless enough to try anyway.

A more recent placebo-controlled trial of 250 mg bisglycinate found insomnia severity fell further than placebo — p=0.049, Cohen’s d=0.2. Statistically significant by the narrowest possible margin, with a small effect size. No significant differences on any other psychological outcome.

• MetaMah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: systematic review and meta-analysis BMC Complement Med Ther 2021;21:125 · 3 RCTs, 151 participants · GRADE low to very low
• RCTMagnesium bisglycinate supplementation in healthy adults reporting poor sleep: randomized placebo-controlled trial 250 mg elemental daily · p=0.049, d=0.2 · DRKS00031494

Across 38 randomised trials and 2,709 participants at a median 365 mg elemental for a median 12 weeks, magnesium lowered systolic pressure by 2.81 mmHg (95% CI −4.32 to −1.29) and diastolic by 2.05 mmHg.

The subgroups are where it becomes clinically interesting. Hypertensive individuals already on blood-pressure medication saw systolic reductions of 7.68 mmHg, and those with hypomagnesemia 5.97 mmHg — both p<0.05.

Heterogeneity was high and no dose-response relationship was detectable (all p≥0.20), so the reviewers advise caution and call for larger trials at higher doses.

• MetaMagnesium supplementation and blood pressure: systematic review and meta-analysis of randomized controlled trials 38 RCTs, 2,709 participants · median 365 mg elemental, 12 weeks

In normotensive groups, statistical significance was not reached — from the same 38-trial analysis that produced a 7.68 mmHg reduction in medicated hypertensives.

This is the population split that matters commercially. Magnesium is sold to the general public as cardiovascular support. The blood pressure effect appears to be a correction in people who are hypertensive or magnesium-deficient, not a benefit in people who are neither.

• MetaMagnesium and blood pressure: normotensive subgroup analysis Statistical significance not reached in normotensive groups

A systematic review of magnesium for self-reported anxiety and sleep concluded that larger randomised trials are needed to confirm efficacy and to establish which forms and doses work.

The reviewers open by noting that magnesium-related videos on TikTok routinely attract hundreds of thousands to millions of views, and that this is precisely why the literature needs to be stated accurately. The 250 mg bisglycinate trial found no significant difference on anxiety, perceived stress or fatigue — only on insomnia severity.

• RevExamining the effects of supplemental magnesium on self-reported anxiety and sleep quality: a systematic review PMID 38817505
• RCTMagnesium bisglycinate trial: secondary psychological outcomes No significant differences observed