Magnesium & Migraines

Magnesium is an essential mineral involved in over 300 biochemical reactions in your body, including nerve transmission, muscle function, and blood vessel regulation. Research has found that many migraine sufferers have lower magnesium levels than people without migraines, particularly during attacks.

Magnesium plays a role in several processes relevant to migraines. It helps regulate neurotransmitter release, maintains healthy blood vessel tone, and blocks the NMDA receptor, which is involved in pain signaling and cortical spreading depression (the wave of nerve activity thought to cause migraine aura). Low magnesium may make the brain more susceptible to the electrical changes that trigger migraine attacks.

Not all magnesium supplements are equal for migraines. The forms with the best evidence include magnesium oxide (400-600 mg daily), magnesium citrate, and magnesium glycinate. Magnesium oxide contains the most elemental magnesium per tablet but has lower absorption rates. Magnesium citrate and glycinate are better absorbed and tend to cause fewer digestive side effects.

The American Academy of Neurology and the American Headache Society have given magnesium a Level B recommendation for migraine prevention, meaning it is "probably effective." Most studies showing benefit used 400-600 mg of magnesium daily. It can take up to three months of consistent use before the full preventive effect becomes apparent.

Magnesium supplements are generally well tolerated, which is one of their biggest advantages over prescription preventives. The most common side effect is loose stools or diarrhea, especially with magnesium oxide and citrate forms. Starting at a lower dose and gradually increasing can help your body adjust.

Magnesium glycinate tends to cause the least digestive upset. People with kidney disease should be cautious with magnesium supplements, as the kidneys are responsible for clearing excess magnesium from the body. At recommended doses, serious side effects are rare for people with normal kidney function. Magnesium can interact with certain antibiotics and bisphosphonates, so check with your pharmacist if you take other medications.

Several clinical trials support magnesium for migraine prevention. A landmark study found that 600 mg of magnesium citrate daily reduced migraine frequency by 41.6% compared to 15.8% with placebo. Other studies have shown similar results with magnesium oxide. The effect is modest compared to prescription preventives but significant, especially considering the favorable side effect profile.

Magnesium appears to be particularly helpful for migraines with aura and for menstrual migraines. Some researchers believe this is because aura involves cortical spreading depression, which magnesium can help suppress. For people who prefer starting with a natural approach or who want to add something to their existing treatment, magnesium is often recommended as a first step.

Because magnesium's effects are gradual and more subtle than prescription medications, consistent tracking is the only reliable way to know if it's working for you. Start logging your migraines in CalmGrid before beginning supplementation to establish a clear baseline.

After three months of daily magnesium, compare your data. Look at monthly migraine frequency, severity, duration, and how well your acute treatments work. Some people notice a reduction in aura frequency even if overall attack numbers don't change dramatically. Without tracking, these gradual improvements can be easy to miss, and you might stop a supplement that was actually helping.