Rankings / Essentials — Vitamins & Minerals
Magnesium
Essentials · Mineral
Tier B+
Bottom line
Read Off Label grades Magnesium as B+ (7.1/10) based on moderate evidence, moderate benefit magnitude, and a low-risk safety profile.
Form matters a lot.
Typical use: 200-400 mg elemental magnesium/day; glycinate for sleep, threonate for cognition, citrate/oxide for constipation — OTC.
What this is
Form matters a lot. Oxide is cheapest but poorly absorbed and laxative. Glycinate is gentler and well-absorbed for general use. Threonate (MgT, Magtein) is marketed for brain penetration based on Slutsky 2010 preclinical data; real-world cognitive benefits modest. Take on empty stomach or with minimal food for best absorption.
Mechanism
NMDA receptor antagonism; GABA-A modulation; cofactor for 300+ enzymes; deficiency very common due to soil/diet; glycinate well-tolerated GI; threonate penetrates CSF better per Slutsky 2010
Dose & route
200-400 mg elemental magnesium/day; glycinate for sleep, threonate for cognition, citrate/oxide for constipation
Citations
- https://pubmed.ncbi.nlm.nih.gov/23853635/
- https://pubmed.ncbi.nlm.nih.gov/20152124/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5786912/
- https://doi.org/10.37489/2587-7836-2025-4-105-111
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5852744/
- https://pubmed.ncbi.nlm.nih.gov/27329332/
- https://www.nature.com/articles/ejcn2016154
Links go to the source. If a link is dead or you want something re-checked, let me know.
Common questions
- Does Magnesium work?
- Read Off Label rates the evidence for Magnesium as Moderate and the benefit magnitude as moderate, producing an overall grade of B+ (7.1/10). Form matters a lot.
- Is Magnesium safe?
- Magnesium has a low risk profile in published human data. Legal status: OTC. This is not medical advice — see the disclaimer.
- What is the typical dose for Magnesium?
- 200-400 mg elemental magnesium/day; glycinate for sleep, threonate for cognition, citrate/oxide for constipation
- How does Magnesium work?
- NMDA receptor antagonism; GABA-A modulation; cofactor for 300+ enzymes; deficiency very common due to soil/diet; glycinate well-tolerated GI; threonate penetrates CSF better per Slutsky 2010
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.