Substrate ·evidence-based
interventions / Magnesium / heart health

Does Magnesium help heart health? (Grade B evidence)

Grade B for Magnesium on heart health: the balance of RCT evidence favours a benefit, especially in adults, at moderate certainty, at doses median ~365 mg/day elemental magnesium, ~12 weeks.

Exact question reviewed

Population
adults
Intervention
Magnesium · median ~365 mg/day elemental magnesium, ~12 weeks
Comparator
not reported
Outcome
heart health
Time horizon
not reported

Bottom line. Grade B for Magnesium on heart health: the balance of RCT evidence favours a benefit, especially in adults, at moderate certainty, at doses median ~365 mg/day elemental magnesium, ~12 weeks. [1 RCT]

Direction
benefit
Magnitude
Meta-analysis of 38 RCTs (2709 participants): magnesium supplementation modestly lowered blood pressure — systolic by about 2.8 mm Hg and diastolic by about 2.0 mm Hg versus control. A small but consistent blood-pressure effect; not shown to reduce cardiovascular events directly.
Grade
B
Certainty
moderate
Clinical meaning
small but potentially useful
Who it applies to
adults
Dose / form studied
median ~365 mg/day elemental magnesium, ~12 weeks
Safety
minor_with_ssri
The one limitation
Claim-specific limitation details are not available in this public record.

Reviewed · Evidence last changed · Claim clm_ec_b7-mg-heart v0

⚠ Safety in context

Grade
B
what does the grade mean?
Certainty
moderate
what does certainty mean?

Grade B / moderate: probably helps, and new studies are unlikely to reverse this — but could shrink the effect size.

Who it works for

Best-studied in adults. Recorded studied dose: median ~365 mg/day elemental magnesium, ~12 weeks.

Evidence

StudyDesignRoleCite
Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.peer-reviewedsupportsPMID:41000008

Why this grade

Reasoning trace

The current record stores Grade B at moderate certainty and links 1 publishable source. A claim-specific domain-by-domain grading rationale is not available in this public record, so no reason for upgrading or downgrading is inferred here.

Audit and version

Claim ID
ec_b7-mg-heart
Claim version
not reported
Governance
legacy, not verified
Last evidence search
not reported
Last editorial review
2026-07-16T16:23:36.633Z

Public receipt · Machine-readable claim · Methodology

Dose & form

Studied intake: median ~365 mg/day elemental magnesium, ~12 weeks.

Full dose & form comparison for Magnesium →

How it stacks up for heart health

Grade history

No grade changes yet. Initial grade assigned; re-reviewed on every 12 months (Grade A/B) — next review by . Methodology v1.

Re-review cadence: every 12 months (Grade A/B) · next scheduled by · methodology v1.

Frequently asked

How long does Magnesium take to work for heart health?

Trials of Magnesium for heart health typically report effects within 2–4 weeks, though individual response varies. Studies rarely find benefit inside 1 week for chronic outcomes.

What dose was used in studies of Magnesium for heart health?

Studied doses for Magnesium in heart health trials cluster around median ~365 mg/day elemental magnesium, ~12 weeks. See the dose block for the specific range and how it varies by form.

Does Magnesium work for heart health if I'm not deficient?

The effect concentrates in adults. If your baseline is normal, expect a smaller effect than the trial averages.

Magnesium or the next-best alternative for heart health?

See the compare block above for the head-to-head with the most-cited alternative. Grade + certainty differences matter more than any single trial.

Related

What this is — and is not

Evidence description
Meta-analysis of 38 RCTs (2709 participants): magnesium supplementation modestly lowered blood pressure — systolic by about 2.8 mm Hg and diastolic by about 2.0 mm Hg versus control. A small but consistent blood-pressure effect; not shown to reduce cardiovascular events directly.
Substrate's interpretation
The current reviewed record assigns Grade B at moderate certainty. A domain-by-domain rationale is shown only when recorded.
Discuss with a clinician
If you're on medication or have a condition that changes the calculus, bring the interaction & population blocks above to your pharmacist or prescriber before deciding.
Individualized medical advice
Not provided here or on any Substrate surface (API, agent tool, embed) — see YMYL policy.

Cite this page

Citation is encouraged. The proposed reuse license is CC-BY-4.0; status: pending-governance-ratification.

Plain-text citation
Substrate. Does Magnesium help heart health? (Grade B). https://evidencebased.info/interventions/magnesium/heart-health. Updated 2026-07-16.
BibTeX
@misc{substrate_magnesiumhearthealth,
  author = {Substrate editorial},
  title  = {Does Magnesium help heart health?},
  year   = {2026},
  url    = {https://evidencebased.info/interventions/magnesium/heart-health},
  note   = {Grade B, evidencebased.info}
}

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