tuneTypical Dose
200–400
Mineral
Magnesium Glycinate
Magnesium bisglycinate (Mg bound to glycine)
Evidence TierBWADA NOT PROHIBITED
watchEffect Window
Acute relaxation within 30-60 min. Deficiency correction over weeks.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Magnesium glycinate is magnesium bound to glycine, often chosen for better gastrointestinal tolerance. It is used to raise magnesium status and support relaxation and sleep quality goals.
Magnesium glycinate is still used mainly for tolerance and adherence rather than for uniquely strong glycinate-specific efficacy. A newer placebo-controlled bisglycinate trial found a modest improvement in insomnia severity over 4 weeks, with the clearest benefit in adults whose magnesium intake was likely low at baseline. That supports practical use for poor sleepers who may be under-consuming magnesium, but it does not prove large sleep effects in magnesium-replete adults.
Magnesium acts as an NMDA receptor antagonist. Glycine is an inhibitory neurotransmitter, and the chelate delivers calming effects from both molecules with superior gut absorption.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- sleep quality
- magnesium deficiency correction
- muscle relaxation
Secondary Outcomes
- anxiety reduction
- reduced GI distress vs other Mg forms
Safety
Contraindications and Interactions
Contraindications
- Severe kidney disease
- Myasthenia gravis
Side effects
- Generally very well tolerated
- Rare mild drowsiness
Interactions
- Bisphosphonates (separate 2h)
- Tetracyclines (separate 2h)
- Fluoroquinolones (separate 2h)
Avoid if
- Severe renal impairment
Evidence
Study-level References
magnesium-glycinate-SRC-001Randomized, double-blind, placebo-controlled parallel trial
Sourceopen_in_newSchuster J, Cycelskij I, Lopresti AL, Hahn A. Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial. Nat Sci Sleep. 2025;17:2027-2040. doi:10.2147/NSS.S524348. PMID:40918053.
Population: Healthy adults reporting poor sleep quality.
Dose protocol: 250 mg elemental magnesium daily as magnesium bisglycinate for 4 weeks
Key findings: Insomnia Severity Index scores improved more than placebo, though the effect size was small and other psychological outcomes did not differ.
Notes: This is a better modern anchor than the prior unsourced bioavailability claim because it captures a real glycinate-specific human outcome.
Paper content
This open-access parallel RCT randomized 155 adults with poor sleep to 250 mg elemental magnesium as bisglycinate or placebo for 4 weeks. The active group showed a modest but statistically significant between-group advantage on the Insomnia Severity Index, with a small effect size and no clear benefit on broader fatigue, stress, or mood questionnaires. Exploratory subgroup analyses suggested larger improvements in participants with lower baseline magnesium intake, which supports practical use in likely low-intake sleepers more than it supports a large class-wide sleep claim for magnesium glycinate in magnesium-replete adults.