
Rugby Magnesium Oxide 400 mg Tablets - Dietary Supplement…
Cost per serving
$0.04
360 servings · ~360-day supply
Magnesium is one of the few supplements headache guidelines list for preventing migraines, taken daily rather than during an attack. Below, the magnesium products people use ranked by real cost per dose (to the commonly-studied 300 mg dose). A value comparison, not medical advice.
Updated September 2026
Moderate. The 2012 American Academy of Neurology / American Headache Society guideline rated magnesium “probably effective” (Level B) for preventing migraine, based on trials of about 600 mg a day. Results were mixed, diarrhea is common at that dose, and 600 mg is above the 350 mg supplement upper limit — agree it with a doctor. It prevents attacks over months; it does not stop one in progress.
Commonly used: ~600 mg/day in trials, taken daily for about 3 months.
How this list is built: these are magnesium products ranked by real cost per dose across our whole magnesium catalogue — not filtered or re-ordered by migraine prevention. We don’t hold per-product evidence for a specific use, so we don’t pretend to rank for one. Products whose own label says they are for something else are left out.
Background on magnesium from the NIH Office of Dietary Supplements .

Rugby Magnesium Oxide 400 mg Tablets - Dietary Supplement…
Cost per serving
$0.04
360 servings · ~360-day supply

Advanced Electrolyte Complex Capsules for Hydration
Cost per serving
$0.04
240 servings · ~240-day supply

Rugby Magnesium Oxide 400 mg Tablets - Dietary Supplement…
Cost per serving
$0.05
120 servings · ~120-day supply

Swanson Magnesium 200 Milligrams 250 Capsules
Cost per serving
$0.05
250 servings · ~250-day supply

PURE ORIGINAL INGREDIENTS Cayenne Pepper (730 Capsules) No…
Cost per serving
$0.05
730 servings · ~730-day supply

Amazing Formulas Calcium Magnesium Zinc D3-300 Tablets Per…
Cost per serving
$0.05
300 servings · ~300-day supply

Nutricost Potassium (99 mg) Magnesium (210 mg) Citrates
Cost per serving
$0.06
240 servings · ~240-day supply

Advanced Electrolyte Pills
Cost per serving
$0.06
240 servings · ~240-day supply

Magnesium Malate Capsules (420 Count) - 1,500mg Per Serving…
Cost per serving
$0.06
420 servings · ~420-day supply
See the full ranking, benchmarks and lab-tested brands on best magnesium by cost per dose.
Moderate. The 2012 American Academy of Neurology / American Headache Society guideline rated magnesium “probably effective” (Level B) for preventing migraine, based on trials of about 600 mg a day. Results were mixed, diarrhea is common at that dose, and 600 mg is above the 350 mg supplement upper limit — agree it with a doctor. It prevents attacks over months; it does not stop one in progress. This page ranks the products people take by real cost per dose; it does not claim a supplement treats or cures anything. Not medical advice — talk to a clinician about migraine prevention.
As of September 2026, the best value we track is Rugby Magnesium Oxide 400 mg Tablets - Dietary Supplement - Gluten-Free - 120 Count (3 Pack). The full ranking by cost per dose is above; Price ÷ servings ÷ dose — the number retailers rarely divide out.
Commonly ~600 mg/day in trials, taken daily for about 3 months. This is a general reference, not a prescription — confirm the right amount for you with a clinician. Not medical advice.