Magnesium's Effect on Sleep, Insomnia, and Restless Leg Syndrome
50% of older adults suffer from insomnia, a condition characterized by difficulty falling asleep, staying asleep, and waking up refreshed 1. Research indicates that there is a direct relationship between magnesium intake and sleep disturbances, insomnia, and restless leg syndrome (RLS). Essentially, magnesium inhibits excitatory NMDA receptor activity in the brain, and promotes GABA-A receptor activity—a process that stimulates relaxation, which in turn allows one to fall asleep 2.
The physiological causes of sleep disturbances and anxiety are similar.
A double-blind clinical trial of older adults with insomnia found that 500 mg of magnesium per day, given as an oral supplement, significantly increased sleep time and sleep efficiency. It also significantly decreased insomnia severity scores and sleep onset latency (length of time needed to fall asleep), among other advantageous benefits 1.
In terms of restless leg syndrome, how magnesium improves this condition is not understood at all; however, supplementation with 300 mg of magnesium daily was shown to significantly decrease periodic limb movements and improve sleep efficacy and overall sleep quality for those suffering from mild to moderate RLS caused by insomnia 3.
1. Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences: The Official Journal of Isfahan University of Medical Sciences. 2012;17(12):1161-1169. [PMC]
2. Schwalfenberg GK, Genuis SJ. The importance of magnesium in clinical healthcare. Scientifica (Cairo). 2017;2017:4179326. [PubMed]
3. Hornyak M, Voderholzer U, Hohagen F, Berger M, Riemann D. Magnesium therapy for periodic leg movements-related insomnia and restless legs syndrome: An open pilot study. Sleep. 1998;21(5):501. [Pubmed]