<unk>  is generally not a harmful substance, but care should be taken by consulting a healthcare professional if any adverse health problems are suspected or experienced. Extreme magnesium overdose can result in serious complications such as slow heart beat, low blood pressure, nausea, drowsiness, etc. If severe enough, an overdose can even result in coma or death. However, a moderate overdose will be excreted through the kidneys, unless one has serious kidney problems. Rectal bleeding or failure to have a bowel movement after use could be signs of a serious condition.
Magnesium citrate
Magnesium sulfate
Magnesium sulfate 
Disufenton sodium
Sodium thiosulfate 
Ferrous tartrate
Calcium chloride
Potassium fluoride