Supplement analysis backed by scientific evidence · PT

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Limited evidenceHeart & metabolic

Magnesium Orotate

Sold on one striking heart-failure trial from 2009 that has never been replicated, and delivers very little actual magnesium per capsule. The premium is not justified by the evidence, and the doses that produced the famous result are far higher than any consumer product provides.

What the science says

  • The heart failure result rests on a single small trial Limited evidence

    The MACH trial randomised 79 patients with NYHA class IV heart failure on optimal medication to magnesium orotate (6,000 mg/day for 1 month, then 3,000 mg/day for about 11 months) or placebo, reporting 1-year survival of 75.7% versus 51.6% and symptom improvement in 38.5% versus deterioration in 56.3% on placebo. A 24-percentage-point survival gain from a mineral salt in advanced heart failure would be extraordinary — it comes from one monocentric study, required an erratum and a corrected republication, has never been reproduced, and has not entered any heart failure guideline.

  • Supporting cardiac data are thin Limited evidence

    A 1998 study reported improved exercise tolerance in patients with coronary heart disease given magnesium orotate, alongside a companion review of orotic acid's proposed role in myocardial energy metabolism. These are small, old, and from a research group closely associated with the compound.

  • Very low elemental magnesium content Moderate evidence

    Magnesium orotate is roughly 7% elemental magnesium by weight, so a 500 mg capsule delivers about 32 mg — under a tenth of the adult RDA. Reaching the 3,000-6,000 mg/day used in MACH would mean 6-12 grams of capsules daily, which no commercial product is dosed for.

Dosage & safety

Studied doseTrials used 3,000-6,000 mg magnesium orotate per day (roughly 200-400 mg elemental magnesium). Consumer products typically provide 500-800 mg of the salt, i.e. 35-55 mg elemental — a token dose if magnesium repletion is the goal.
SafetyGastrointestinal upset and loose stools, as with any magnesium salt; avoid in advanced chronic kidney disease because of hypermagnesemia risk. Gram-level orotic acid intake is the less-discussed issue: orotic acid promotes hepatic fat accumulation in rodent models and long-term human safety at multi-gram daily doses has not been established. Separate by 2 hours from tetracyclines, quinolones, bisphosphonates and levothyroxine. Not banned in sport.

Scientific references

Where to buy

Nutricost, Magnesium Orotate, 120 Capsules (35 mg per Capsule)

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