It depends what kind of magnesium, they are not all the same. Magnesium doesn't mean anything, you have to know if it's magnesium carbonate, citrate, etc, and its origin, marine magnesium is good, but the best one in my opinion is magnesium chloride, but even with magnesium chloride, you take it as much you don't have bad effects, bad effects for magnesium chloride are diarrhea and some stomach burnings, but the form is very healthy, and you will see real improvements in your health, and the way your body can fight viruses and germs. Have 20mg in one liter, and take half a glass a day, or if you can't stand the taste (very bad taste, not everyone can take it), buy Delbiase, it's a true miracle, it's a French medicine based on Dr Delbet works, this French doctor was the man who studied the most magnesium effects as far as I know.