From what I've read, magnesium can make your MG muscle weakness worse because it blocks nerve signals from reaching muscles. Magnesium can also cause increased fatigue, uncontrolled facial muscle movement, and an abnormal heartbeat in persons with MG. But when I had my MG crisis in Jan 2023, my magnesium was very low and they kept giving me IVs with magnesium - and I felt much better.

I take magnesium daily and don’t have any problems . We are all so different. I also do it topically as a spray for muscle pain and cramping.