I take magnesium every day and its far from dangerous. Look at what's in supplements and in food. Magnesium is in everything. So obviously its not dangerous. I think its more of a myth. Magnesium is only bad if you have poor fluid intake and the concern is dehydration. But if you suffer from constipation you should be drinking LOTS of water any way and this should not be a concern. I had brought this up with my doctor and he told me the same thing. Drink lots of water and you will be fine.