Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis

Three randomized, double-blind, placebo-controlled trials; 151 older adults across three countries; participants largely without comorbidities (no sleep-related breathing or movement disorders).

Oral magnesium oxide or magnesium citrate; total daily elemental magnesium 320–729 mg, taken in 2–3 divided doses, for 20 days to 8 weeks.

Magnesium reduced sleep onset latency by 17.36 minutes vs placebo (95% CI −27.27 to −7.44; p=0.0006); total sleep time increased by 16.06 minutes but not statistically significant. Sleep questionnaire outcomes showed inconsistent, low-certainty improvements; no adverse events reported. Overall evidence quality is low to very low due to bias and heterogeneity. Clinically, due to low cost and wide availability, oral magnesium may be considered for insomnia symptoms in older adults at doses under 1 g per dose, up to 3 times daily, but more rigorous trials are needed to confirm benefit and safety.

Three small RCTs (n=151) with moderate-to-high risk of bias and low-to-very-low quality evidence; inconsistent outcome measures; no adverse event data; short and variable trial durations; limited generalizability.