Mineral

Magnesium

Magnesium (Mg, element 12)

Evidence TierAWADA NOT PROHIBITED

tuneTypical Dose

300 mg

watchEffect Window

Acute relaxation within hours. Deficiency correction over 2-4 weeks.

check_circleCompliance

WADA NOT PROHIBITED

Overview

Clinical Summary

Magnesium is an essential mineral involved in neuromuscular function and hundreds of enzymes. It is used to correct low intake and to support sleep, cramps, migraine prevention, and blood pressure control.

Restoring low magnesium status can reduce cramps and fatigue and support normal cardiac rhythm. Trials show modest blood pressure reductions, with larger effects in hypertension or low magnesium status, and reduced migraine frequency in some people. Minority evidence suggests improved sleep quality and insulin sensitivity, particularly with low baseline status. Gastrointestinal tolerance varies by form and dose, which can determine usable intake.

Cofactor for >300 enzymatic reactions. NMDA receptor antagonist reducing neuronal excitability. Regulates GABA, melatonin, and cortisol.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Deficiency correction
  • Muscle cramp relief
  • Blood pressure reduction

Secondary Outcomes

  • Sleep quality improvement
  • Anxiety reduction
  • Migraine frequency reduction

Safety

Contraindications and Interactions

Contraindications

  • Severe renal failure
  • Myasthenia gravis
  • Heart block

Side effects

  • Diarrhea and loose stools (dose-limiting, especially oxide/citrate forms) - Taking magnesium in divided doses may reduce diarrhea. Certain magnesium salts (e.g., magnesium gluconate, magnesium chloride) may be less likely to cause diarrhea.
  • Abdominal pain and GI cramping
  • Nausea at higher doses
  • Bone pain
  • Muscle weakness
  • Itching
  • Tingling
  • Skin flushing
  • Sweating

Interactions

  • Bisphosphonates (Probable/Moderate) - Magnesium can reduce bisphosphonate absorption. Separate dosing by at least 2 hours.
  • Tetracycline antibiotics (Probable/Moderate) - Magnesium can reduce tetracycline absorption. Separate dosing by at least 2 hours.
  • Fluoroquinolone antibiotics (Probable/Moderate) - Magnesium can reduce fluoroquinolone absorption. Separate dosing by at least 2 hours.
  • Muscle relaxants/neuromuscular blockers (Possible/Moderate) - Magnesium may potentiate neuromuscular blockade.
  • Loop and thiazide diuretics (Possible/Moderate) - These can increase magnesium excretion and alter magnesium status.
  • Digoxin (Probable/Moderate) - Magnesium may reduce the absorption of digoxin when administered together, leading to decreased drug levels.
  • Levodopa (Probable/Moderate) - Magnesium may reduce the absorption of levodopa when administered together, leading to decreased drug levels.
  • Carbidopa (Probable/Moderate) - Magnesium may reduce the absorption of levodopa when administered together, leading to decreased drug levels.
  • H2-receptor antagonists (Probable/Moderate) - Magnesium may reduce H2-receptor antagonist absorption when administered together, leading to decreased drug levels.
  • Vericiguat (Possible/Moderate) - Magnesium might reduce the absorption of vericiguat when administered together, leading to decreased drug levels, which could reduce the effectiveness of vericiguat.
  • Gabapentin (Possible/Moderate) - Magnesium may reduce the absorption of gabapentin when administered together, leading to decreased drug levels.
  • Iron (Possible/Moderate) - Magnesium may reduce the absorption of iron when administered together, potentially reducing the effectiveness of iron supplements.
  • Nitrofurantoin (Possible/Moderate) - Magnesium may reduce the absorption of nitrofurantoin when administered together, leading to decreased drug levels, which could impair the effectiveness of nitrofurantoin.

Avoid if

  • People with severe kidney disease
  • People on dialysis without physician guidance
  • People using digoxin
  • People using levodopa
  • People using carbidopa
  • People using H2-receptor antagonists
  • People using vericiguat
  • People using gabapentin
  • People using iron
  • People using nitrofurantoin

Evidence

Study-level References

magnesium-SRC-001Meta-analysis
Sourceopen_in_new

Zhang X, et al. "Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of Randomized Double-Blind Placebo-Controlled Trials." Hypertension. 2016.

Population: Adults (Hypertensive and Normotensive)

Key findings: Magnesium supplementation results in a small but significant reduction in blood pressure.

Paper content

Magnesium supplementation results in a small but significant reduction in blood pressure.

magnesium-SRC-002Randomized double-blind placebo-controlled trial
Sourceopen_in_new

Hausenblas HA, et al. Magnesium-L-threonate improves sleep quality and daytime functioning: randomized controlled trial. Sleep Med X. 2024;8:100121. PMID:39252819

Population: Adults (35-55 years) with self-reported sleep problems (n=80)

Dose protocol: 1 g/day magnesium L-threonate for 21 days

Key findings: Randomized trial showed improved subjective sleep quality and daytime functioning, with some selected objective sleep improvements.

Notes: Form-specific evidence. Do not generalize this directly to every magnesium salt.

Paper content

Improved subjective sleep/daytime metrics; selected objective improvements

magnesium-SRC-003Randomized double-blind placebo-controlled trial
Sourceopen_in_new

Schuster J, Cycelskij I, Lopresti A, 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 aged 18-65 years with self-reported poor sleep quality.

Dose protocol: Magnesium dose and form varied substantially across pooled sleep trials.

Key findings: Updated meta-analysis suggested modest subjective sleep-quality benefit, but certainty remained limited by heterogeneity and short study duration.

Notes: Supports keeping sleep claims cautious and not treating all magnesium forms as interchangeable.

Paper content

Updated pooled evidence suggested modest improvement in subjective sleep quality, but certainty remained limited by heterogeneity, short trials, and form-specific differences.

magnesium-SRC-004Systematic review and meta-analysis of randomized controlled trials
Sourceopen_in_new

Argeros Z, Xu X, Bhandari B, Harris K, Touyz RM, Schutte AE. Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Hypertension. 2025;82(11):1844-1856. doi:10.1161/HYPERTENSIONAHA.125.25129. PMID:41000008.

Population: Adults in 38 randomized trials evaluating oral magnesium supplementation and blood pressure.

Dose protocol: 82.3-637 mg elemental magnesium daily across trials, with a median dose of 365 mg for about 12 weeks.

Key findings: Updated meta-analysis found modest overall reductions in systolic and diastolic blood pressure, with larger effects in hypertension and hypomagnesemia.

Notes: Helps keep the blood-pressure claim population-specific instead of implying a universal effect.

Paper content

Updated pooled evidence supports modest blood-pressure lowering with oral magnesium, especially in people with hypertension or low magnesium status, while normotensive populations did not show a clear significant effect. The review did not identify a convincing dose-response relationship across the included range.

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