Does 400 mg magnesium glycinate at night reduce my migraine days?

Background

I get 2–4 migraine days most weeks. A neurologist mentioned magnesium as a low-risk thing some people try, so I decided to test it on myself properly rather than just "see how it goes."

Method

I used an ABAB design: alternating 3-week blocks with no magnesium (A) and 3 weeks of 400 mg magnesium glycinate taken ~30 minutes before bed (B). I kept a simple headache diary in my notes app every morning, logging whether I had a migraine the previous day and, if so, the peak pain on a 0–10 scale.

I tried to keep everything else constant — caffeine, work schedule, screen habits — though life isn't a lab.

Results

Averaged across blocks, migraine days fell from 2.85/week off to 1.5/week on — roughly a 47% reduction. Pain intensity dropped only slightly.

Discussion

The on/off pattern repeating twice makes me more confident this isn't pure chance. But there are real limitations:

• Unblinded. I knew which phase I was in, so expectation effects are likely.
• Sleep confound. Magnesium seemed to improve my sleep, and poor sleep is one of my migraine triggers — so the effect may be indirect.
• Short blocks. 3 weeks is not long; a single bad week swings the average.

Conclusion

For me, nightly magnesium glycinate is associated with meaningfully fewer migraine days, and the cost/risk is low enough that I'm continuing it. I would not generalize this to anyone else — but I'd love for someone to try a blinded version (e.g., identical-looking capsules) and post their results here.