Also sold as Glycinate, citrate, malate, threonate
A common shortfall from depleted soils and high stress. Form changes what it does.
TrustedSupp Tier System™ · Tier 2Take until levels correct
Check before you startThis one has documented interactions with medication classes where the consequences are serious. If you take any prescription medicine, run it past a pharmacist before starting.
Evidence strength
70/100Strong
WEAKLIMITEDMODERATESTRONGVERY STRONG
What the evidence supports: correcting deficiency; sleep and cramp claims are weaker.
This scores how well-supported the claim above is — not how much benefit you personally would get. A high score on a narrow claim does not extend to everything the product is marketed for.
How long to take it
Months rather than years for most people. Reassess once sleep, cramps, or stress have settled and food can carry it.
Who it's actually for
People under sustained stress, heavy exercisers, poor sleepers, and those on long-term acid blockers or diuretics.
Safe upper limit
Verified
350 mg per day from supplements (no limit from food)
Excess supplemental magnesium causes diarrhoea first. In kidney impairment it can accumulate dangerously.
Applies to supplemental magnesium only, not dietary. A 2023 peer-reviewed paper argues this 1997 figure is outdated (Costello et al., Adv Nutr) — the official number hasn't changed, but the debate is real.
Interactions to know about
Antibiotics — Especially tetracyclines and quinolones