Supplement Insider Evidence-based wellness
Ingredients / Magnesium glycinate
Moderate evidence overall 13 articles · reviewed 2 Sep 2026

Magnesium glycinate

Magnesium bisglycinate chelate

A well-absorbed magnesium salt. The sleep case is real but narrower than the category implies — it is strongest in people who were short of magnesium to begin with.

What the evidence supports

Moderate Sleep onset Shorter time to fall asleep in older adults and in people with low dietary intake. Null in replete young adults.
Moderate Correcting deficiency Reliably raises serum and red-cell magnesium, with better GI tolerance than oxide.
Limited Anxiety Small trials with symptom-scale outcomes, high risk of bias, inconsistent dosing.
Limited Muscle cramps Repeatedly tested in nocturnal leg cramps and repeatedly null.
Dose used in trials
200–400 mg

of elemental magnesium per day, taken in the evening. Glycinate needs a larger tablet mass for the same elemental dose.

Safety
Gentle on the gut

Loose stools are the dose-limiting effect and are far less common than with oxide or citrate.

Ask a doctor first if
Three cases

Reduced kidney function, certain antibiotics or bisphosphonates (separate by two hours), or diuretic therapy.

The trials, individually

Open any one for sample size, funding and what it actually measured.

Abbasi et al. · 46 older adults · insomnia
Eight weeks, 500 mg/day. Sleep-onset latency, sleep time and serum melatonin all improved versus placebo. Small, single-site, participants were elderly and likely insufficient at baseline.
Meta-analysis · 3 trials · sleep
Pooled sleep-onset benefit of roughly 17 minutes, with the reviewers rating overall certainty as low and calling for trials in magnesium-replete adults.
Garrison et al. · Cochrane · cramps
No meaningful effect on the frequency or intensity of nocturnal leg cramps in older adults. One of the cleaner null findings in the supplement literature.

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