Magnesium supplementation → Sleep duration and regularity
Higher Magnesium supplementation increases Sleep duration and regularity.
Schuster 2025 found that 250 mg of magnesium bisglycinate a day for four weeks lowered the Insomnia Severity Index by 3.9 points versus 2.3 on placebo in 155 adults who reported poor sleep (P=0.049). Hausenblas 2024 saw better deep and REM scores on magnesium L-threonate versus placebo in 80 people.
Randomized trial · Contested · N=155
Supported by an experiment or a tightly identified design. Read the caveats.
Mechanism
Authors treat a magnesium salt as a sleep aid. They do not isolate one transporter. Schuster, Cycelskij, Lopresti and Hahn assigned 155 adults aged 18 to 65 with self-reported poor sleep to 250 mg elemental magnesium as bisglycinate or placebo for four weeks. ISI fell 3.9 versus 2.3 (P=0.049). Other psychological scales did not differ. Hausenblas, Lynch, Hooper and colleagues assigned 80 adults aged 35 to 55 with self-reported sleep problems to 1 g of magnesium L-threonate or placebo for 21 days. Oura deep-sleep and REM scores moved versus placebo. Subjective energy and mood also moved.
Caveats
Researchers assigned people to a salt or a control, so this is a trial stamp. The ISI difference is small. More papers of the same design do not settle the claim. Schuster is four weeks and P=0.049. Hausenblas is a branded L-threonate and a consumer ring. This is a journal entry, not medical advice and not a reason to take magnesium for insomnia.
Effect
qualitative. Schuster 2025: bisglycinate 250 mg, 4 wk, N=155 poor sleep, ISI -3.9 vs -2.3 P=0.049. Hausenblas 2024: MgT 1 g, 21 d, N=80, deep/REM vs placebo. Nielsen 2011: PSQI improved on both arms.
Nodes
Named confounders
Cite this page
What Causes What. “Magnesium supplementation → Sleep duration and regularity.” https://whatcauseswhat.org/edges/e-magnesium-sleep (atlas updated 2026-09-02).
Papers
- Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial.
J Schuster, I Cycelskij, A Lopresti, A Hahn · 2025 · Nature and science of sleep
- Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial.
HA Hausenblas, T Lynch, S Hooper, A Shrestha, D Rosendale, J Gu · 2025 · Sleep medicine: X