Magnesium

Does magnesium help you sleep?

Updated 10 Nov 2026

Short answer

Possibly a little, but the evidence is weak. A 2026 review of 12 trials found inconsistent results, with low to very low certainty, and did not support magnesium as a routine treatment for insomnia.[1] In older adults with insomnia, 3 small trials found that people fell asleep about 17 minutes faster.[2]

What the reviews found

A 2026 review included 12 randomized trials of magnesium alone in adults with insomnia or poor sleep.[1] The trials differed in the people they enrolled, the form and dose of magnesium, how long they lasted and how they measured sleep.[1] Results did not agree across sleep questionnaires, brain-wave recordings (EEG), activity trackers and other body measures.[1]

The authors rated the certainty of the evidence low to very low.[1] They concluded that magnesium may help some adults on some self-reported measures, but that the evidence does not support it as a routine treatment for insomnia.[1] Three more trials, on leg cramps, restless legs or limb movements during sleep, were analysed separately.[1]

A 2021 review looked only at older adults with insomnia. It found 3 trials with 151 people in three countries:[2]

  • People on magnesium fell asleep 17.36 minutes faster than people on placebo.[2]
  • Total sleep time was 16.06 minutes longer, but this difference could be due to chance.[2]
  • All 3 trials had a moderate to high risk of bias, and the quality of the evidence was low to very low.[2]

A 2022 review of 9 studies with 7,582 adults found that people with more magnesium in their diet or blood tended to sleep better in observational studies. These studies linked magnesium status with daytime sleepiness, snoring and sleep duration. The trials in that review gave contradictory results.[3]

A recent trial

In a 2025 trial, 155 adults aged 18 to 65 who reported poor sleep took 250 mg of magnesium a day as magnesium bisglycinate, or a placebo.[4] After 4 weeks, the insomnia score fell by 3.9 points with magnesium and by 2.3 points with placebo. The authors called the effect small.[4] People who ate less magnesium seemed to gain more, but this was an exploratory finding.[4]

Older adults

The 2021 review studied only older adults.[2] Older adults are more likely than younger adults to be low on magnesium: they eat less of it, absorb less and lose more in urine.[5]

Night-time leg cramps

Cramps that wake people at night are a separate question. A Cochrane review found magnesium unlikely to prevent leg cramps in older adults.[6]

What is still unknown

The 2026 review calls for larger, well-designed trials before any routine advice.[1] The 2022 review asks for trials that last longer than 12 weeks.[3] The 2025 trial asks for objective sleep measures and longer trials.[4]

Who should be careful

The US upper limit for magnesium from supplements is 350 mg a day for adults. High doses often cause diarrhea, and people with kidney disease have a higher risk of magnesium toxicity.[5] People who take a medicine every day should ask a doctor or pharmacist first.[5]

Sources (6)

  1. Magnesium Supplementation for Sleep in Adults: A Systematic Review of Randomized Controlled Trials. Lopresti AL, Smith SJ, Drummond PD J Diet Suppl, 2026. PMID 42661485
  2. Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis. Mah J, Pitre T BMC Complement Med Ther, 2021. PMID 33865376
  3. The Role of Magnesium in Sleep Health: a Systematic Review of Available Literature. Arab A, Rafie N, Amani R, Shirani F Biol Trace Elem Res, 2023. PMID 35184264
  4. Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. Schuster J, Cycelskij I, Lopresti A, Hahn A Nat Sci Sleep, 2025. PMID 40918053
  5. Magnesium: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  6. Magnesium for skeletal muscle cramps. Garrison SR, Korownyk CS, Kolber MR, Allan GM, Musini VM, Sekhon RK, et al. Cochrane Database Syst Rev, 2020. PMID 32956536

More about magnesium

What is magnesium?Which foods are good sources of magnesium?What does elemental magnesium mean on a supplement label?What are magnesium's main benefits?Who is most likely to have low magnesium?Is magnesium safe?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.