everyone is different and reacts differently to different types of magnesium supplements. For me, 250 mg is way too low, for others, it may work. You will know by adjusting your dosage, starting small and working up. I personally welcome diarrhea from my mag doses, but that's just me. Drink lots of water throughout the day and evening tho, for mag to work. Some people get cramps, others don't. It's trial and error.