Is magnesium good for sleep?

Due to its actions as an N-methyl-D-aspartate (NMDA) antagonist and a gamma-aminobutyric acid (GABA) agonist, magnesium is hypothesized to help regulate the sleep/wake cycle and thereby promote healthy sleep.^[1][2] Furthermore, some evidence suggests that magnesium deficiencies are associated with sleep disorders.^[3]

For this reason, magnesium is often promoted as a sleep-enhancing supplement, though there is surprisingly little evidence to support this claim.

One meta-analysis of small clinical studies in older adults with insomnia found that supplemental magnesium may reduce the time it takes to fall asleep by approximately 17 minutes compared to placebo. However, magnesium didn’t seem to improve total sleep time or other aspects of sleep quality in this population.^[1]

One small, open-label, pilot study in participants with restless leg syndrome or periodic leg movement disorder found that supplemental magnesium decreased symptoms, leading to a decreased number of nighttime awakenings and improved sleep efficiency.^[4] Therefore, it seems that magnesium may also facilitate sleep in people with sleep-related movement disorders. Ultimately, more research is required in different populations to determine whether magnesium improves sleep or not.