Educational dose math only — not medical advice, not a product recommendation, and not a pass/fail on whether a supplement will work for you.
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Trial reference

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300 mg elemental per day compared citrate, amino-acid chelate and oxide in healthy adults. The endpoint was absorption (urinary, serum, salivary magnesium), not a symptom — oxide did not separate from placebo.

Educational only — not medical advice. Disclaimer.

Want the outcome before the arithmetic? The reason check opens any registry entry on this page with its trial result first, then compares your daily intake with the studied amount.

NIH DSLD market slice

Median100 mg
Products27,926
Below85%

Bulk CSV dump 16 January 2026 · label entries through 2025. Disclosed amounts only — proprietary blends without gram weights excluded.

Trial floors

Primary

Form-comparison trial (elemental) · 300 mg over 60 days (medium evidence · how we grade this) · Benefit shown — 300 mg elemental per day compared citrate, amino-acid chelate and oxide in healthy adults. The endpoint was absorption (urinary, serum, salivary magnesium), not a symptom — oxide did not separate from placebo.

Other floors

  • Daily value (women) · 320 mg (high evidence · how we grade this) — FDA daily value reference — not a trial dose.

  • Daily value (men) · 420 mg (high evidence · how we grade this) — FDA daily value reference — not a trial dose.

  • Bisglycinate sleep trial (elemental) · 250 mg over 4 weeks (limited evidence · how we grade this) · Benefit shown — 250 mg elemental as bisglycinate beat placebo on Insomnia Severity Index at week 4, but the effect was small (Cohen's d = 0.2) and concentrated in people with low dietary magnesium intake.

Safety red flags

  • Magnesium can build up to unsafe blood levels (hypermagnesemia), above all with reduced kidney function: have your level checked and discuss the need and dose with your prescriber.

Label reading notes

  • Labels may list compound weight (glycinate, citrate, oxide) — convert to elemental magnesium before comparing to trial floors or the FDA daily value.
  • Use the magnesium elemental calculator when the label quotes the salt, not elemental milligrams.
  • Oxide, citrate, and glycinate behaved differently in absorption trials; a high compound weight on oxide often delivers modest elemental magnesium and more laxative effect.
  • Sleep and "calm" blends may bury magnesium inside a multi-ingredient matrix — isolate elemental dose before judging whether you reached a studied repletion range.