Doctor's Best Magnesium Glycinate
A chelated magnesium (glycinate/lysinate) chosen for good absorption and low GI upset versus magnesium oxide. A solid choice for correcting low magnesium intake. Evidence that magnesium improves sleep is limited and preliminary, with small effects mainly in deficient or older adults. Not medical advice.
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What the research says
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“While magnesium bisglycinate significantly improved ISI scores, the mean score at week 4 remained in the subthreshold insomnia range, indicating that supplementation alone is unlikely to eliminate insomnia in many individuals.”
In a 2025 RCT of 155 adults with poor sleep, magnesium bisglycinate (250 mg nightly) reduced Insomnia Severity Index more than placebo at 4 weeks, but the effect was small (Cohen's d ~0.2) and scores stayed subthreshold — a modest, not transformative, benefit.
RCT, Nature and Science of Sleep · 2025 ↗ -
“All trials were at moderate-to-high risk of bias and outcomes were supported by low to very low quality of evidence.”
A systematic review/meta-analysis found only three small trials (151 older adults); sleep-onset latency improved ~17 min vs placebo, but all were at moderate-to-high risk of bias and rated low-to-very-low quality, so firm recommendations can't be made.
Mah & Pitre, BMC Complementary Medicine and Therapies · 2021 ↗ -
“Supplementation of magnesium appears to improve subjective measures of insomnia such as ISI score, sleep efficiency, sleep time and sleep onset latency, early morning awakening, and likewise, insomnia objective measures such as concentration of serum renin, melatonin, and serum cortisol, in elderly people.”
A 2012 double-blind RCT in 46 elderly adults with insomnia reported 500 mg/day elemental magnesium improved sleep time, efficiency, and onset latency vs placebo — a positive but small, single, preliminary trial in a deficiency-prone group.
Abbasi et al., J. Research in Medical Sciences · 2012 ↗
Educational summary of the research — not medical advice. Evidence strength varies and individual results differ; talk to a qualified clinician before changing your health routine.
How it compares
| Magnesium glycinate | Magnesium oxide | Magnesium citrate | |
|---|---|---|---|
| Absorption | Good (organic chelate) | Low (~4%) | Good (organic salt) |
| GI / laxative effect | Gentle, least laxative | Often laxative | Can be laxative |
| Elemental Mg per gram | Lower (heavier molecule) | Highest | Moderate |
| Best use | Daily replenishment, sensitive guts | Cheap dosing / constipation | Replenishment or constipation |
Buy it if
- People whose diet is low in magnesium and who want a well-absorbed form
- Anyone who gets loose stools or cramping from magnesium oxide or citrate
- Older adults or poor sleepers willing to try it knowing the evidence is preliminary
- Supplement users who prefer a vegan, non-GMO chelated form
Skip it if
- People with kidney disease / impaired renal function unless a doctor approves
- Anyone expecting a guaranteed sleep cure — effects are small
- Those who already meet magnesium needs through diet
The verdict
A well-absorbed, gut-friendly glycinate/lysinate chelate — a sensible everyday magnesium for people who don't tolerate cheaper oxide. Be realistic about sleep: the human evidence is limited and preliminary, with small effects concentrated in those who are deficient. A reasonable buy for replenishment, not a proven sleep remedy. Not medical advice.
Check price on Amazon Live price & reviews on AmazonQuestions, answered
- Will magnesium glycinate help me sleep?
- Maybe modestly. Trials show small reductions in insomnia severity, clearest in people low in magnesium or older. The evidence is limited and preliminary — treat it as support for healthy magnesium status, not a reliable sleep aid. Not medical advice. Source Mah & Pitre 2021 meta-analysis, BMC Complement Med Ther ↗RCT 2025, Nature and Science of Sleep ↗
- Why choose glycinate over magnesium oxide?
- Glycinate is an organic chelate that's generally better absorbed and far gentler on the gut, whereas oxide is poorly absorbed (~4%) and more likely to cause loose stools. Oxide does pack more elemental magnesium per tablet and costs less. Source Schwalfenberg & Genuis, Scientifica (PMC, open access) ↗
- How much should I take and is it safe?
- Two tablets supply ~200 mg elemental magnesium. Health authorities set a 350 mg/day upper limit for supplemental magnesium to avoid diarrhea, and people with kidney disease shouldn't supplement without medical guidance. Talk to your doctor first. Source Magnesium UL review, Advances in Nutrition (PMC, open access) ↗