Magnesium and Migraine

Oral magnesium for migraine prophylaxis

A meta-analysis of randomized controlled trials examined magnesium across two distinct uses: oral supplementation taken regularly to prevent migraine, and intravenous infusion given during an acute attack. The prophylaxis arm pooled 10 trials with 789 participants. In that analysis, oral magnesium supplementation was associated with reduced frequency and intensity of migraine compared with control groups, supporting an exploratory role for regular oral magnesium in migraine prevention.^[1]

The specific oral doses and treatment durations varied across the included trials, so the pooled result reflects a range of supplementation regimens rather than a single standardized protocol. Individual responses differ, and these findings describe group-level associations rather than an outcome that can be expected for any one person.^[1]

Intravenous magnesium for acute attacks: mixed evidence

The picture for intravenous magnesium during an acute migraine attack is less consistent. One meta-analysis pooling 11 trials reported that intravenous magnesium relieved acute migraine within 15 to 45 minutes, at 120 minutes, and at 24 hours after the initial infusion. A separate meta-analysis of five double-blind randomized controlled trials, however, did not find a significant benefit for headache relief and reported that adverse events were more common with magnesium than with control. Because these pooled analyses reach different conclusions, the evidence on intravenous magnesium for acute attacks should be interpreted with caution.^{[1], [2]}

Interpreting the evidence

Across this body of work, the more consistent signal is for oral magnesium used as ongoing prophylaxis rather than for intravenous magnesium used acutely. The prophylaxis association comes from pooled randomized controlled trials, while the acute-attack evidence remains divided between analyses. This is general research information and not medical advice; decisions about migraine management should involve a qualified healthcare professional.^{[1], [2]}

Limitations

The prophylaxis meta-analysis noted that some included studies did not use adequate randomization methods, which can bias pooled estimates. Dosing, formulation, and trial duration varied across studies, limiting how precisely an effective oral regimen can be defined from the pooled data.^[1]

For acute treatment, the two meta-analyses disagree, and one reported significantly more side-effects with intravenous magnesium than with control. The conflicting results mean no firm conclusion about intravenous magnesium for acute migraine can be drawn from these analyses.^{[1], [2]}