Magnesium for Sleep: What the New Meta-Analysis Actually Shows

Key findings

A 2026 meta-analysis published in *Sleep Medicine Reviews* pooled data from **12 randomized controlled trials** (n=2,400) examining the effects of magnesium supplementation on sleep parameters.

Primary outcomes

**Sleep onset latency**: Reduced by 12.3 minutes (95% CI: -16.1 to -8.5, p<0.001)

**Sleep quality (PSQI)**: Improved by 0.6 standard deviations (p<0.001)

**Sleep efficiency**: Increased by 3.2 percentage points (p=0.02)

What form of magnesium matters

The subgroup analysis revealed significant differences between forms:

**Glycinate/bisglycinate**: Largest effect on sleep quality (SMD = -0.72)

**Threonate**: Smaller but significant effects, with additional cognitive benefits

**Oxide**: No significant improvement over placebo in any outcome

**Citrate**: Modest effects, primarily on sleep onset

Who benefits most

The effect was strongest in:

Adults over 40 (vs. younger adults)

Those with baseline PSQI scores > 5 (poor sleepers)

Women (though both sexes benefited)

What this means for protocols

This meta-analysis strengthens the evidence for including **300mg magnesium glycinate before bed** as an S-tier recommendation in sleep protocols. We've updated the Sleep Optimization protocol accordingly.

Limitations

Most trials were 8 weeks or shorter

Heterogeneity was moderate (I² = 45%)

Publication bias cannot be ruled out

Magnesium status was not assessed in all trials (those already replete may see less benefit)

References

1. Zhang Y, et al. (2026) Magnesium supplementation and sleep: a systematic review and meta-analysis. *Sleep Medicine Reviews*. DOI: 10.1016/j.smrv.2026.101842

2. Abbasi B, et al. (2012) The effect of magnesium supplementation on primary insomnia. *J Res Med Sci*. 17(12):1161-9

3. Held K, et al. (2002) Oral Mg supplementation reverses age-related neuroendocrine and sleep EEG changes. *Pharmacopsychiatry*. 35(4):135-43