Does Magnesium help migraine frequency? (Grade C evidence)
For migraine frequency, Magnesium sits at Grade C — a hint of benefit in limited trials, especially in adults with migraine, oral prophylaxis, low certainty, at doses not standardized across the 10 oral trials.
Bottom line. For migraine frequency, Magnesium sits at Grade C — a hint of benefit in limited trials, especially in adults with migraine, oral prophylaxis, low certainty, at doses not standardized across the 10 oral trials. [1 RCT]
- Direction
- benefit
- Magnitude
- 10 oral-magnesium RCTs (n=789): reduced migraine frequency and intensity vs. placebo (odds ratios 0.20 and 0.27, no CIs given); some trials had inadequate randomization per the review authors. A separate IV arm covered acute attacks, not prevention.
- Grade
- C
- Certainty
- low
- Clinical meaning
- small but potentially useful
- Who it applies to
- adults with migraine, oral prophylaxis
- Dose / form studied
- Safety
- minor_with_ssri
- The one limitation
- Sample sizes are small in most included trials; effect sizes may shrink with larger studies.
Reviewed · Evidence last changed · Claim clm_ec_b3-mg-migraine v1
⚠ Safety in context
- minorwith SSRI: Generally fine with an SSRI; space about 2 hours apart. full interaction →
Grade C / low: hints of benefit in small trials; a well-run RCT could easily push this to B or to null.
Who it works for
Best-studied in adults with migraine, oral prophylaxis. Effective doses cluster around not standardized across the 10 oral trials.
Evidence
| Study | Design | Cite |
|---|---|---|
| Effects of Intravenous and Oral Magnesium on Reducing Migraine: A Meta-analysis of Randomized Controlled Trials. | peer-reviewed | PMID:26752497 |
Why this grade
Reasoning trace
Grade C at low certainty. The grade reflects the direction and size of the effect across the 1 publishable source above; certainty reflects heterogeneity, sample sizes, and design quality. What would move it upward: additional well-powered RCTs in the target population that replicate the effect at similar doses. What would move it down: a large null trial, discovery of publication bias, or a retraction of a keystone study.
Dose & form
Studied intake: not standardized across the 10 oral trials.
Grade history
No grade changes yet. Initial grade assigned; re-reviewed on every 6 months (Grade C+) — next review by . Methodology v1.
Re-review cadence: every 6 months (Grade C+) · next scheduled by · methodology v1.
Frequently asked
How long does Magnesium take to work for migraine frequency?
Trials of Magnesium for migraine frequency 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 migraine frequency?
Studied doses for Magnesium in migraine frequency trials cluster around not standardized across the 10 oral trials. See the dose block for the specific range and how it varies by form.
Does Magnesium work for migraine frequency if I'm not deficient?
The effect concentrates in adults with migraine, oral prophylaxis. If your baseline is normal, expect a smaller effect than the trial averages.
Magnesium or the next-best alternative for migraine frequency?
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
- 10 oral-magnesium RCTs (n=789): reduced migraine frequency and intensity vs. placebo (odds ratios 0.20 and 0.27, no CIs given); some trials had inadequate randomization per the review authors. A separate IV arm covered acute attacks, not prevention.
- Substrate's interpretation
- Grade C at low certainty — the direction and size the studies converge on, as our reading of the corpus.
- 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
Reuse under CC-BY 4.0 with attribution to evidencebased.info.
Plain-text citation
Substrate. Does Magnesium help migraine frequency? (Grade C). https://evidencebased.info/interventions/magnesium/migraine. Updated 2026-07-16.
BibTeX
@misc{substrate_onsmagnesiummigraine,
author = {Substrate editorial},
title = {Does Magnesium help migraine frequency?},
year = {2026},
url = {https://evidencebased.info/interventions/magnesium/migraine},
note = {Grade C, evidencebased.info}
}Found something wrong on this page? Report an error →