Activated charcoal can help in some emergency poisonings or drug overdoses. If you get it into your system within an hour, it can trap some of the toxins and keep your body from absorbing them. An ER doctor might give it to you through a feeding tube, which goes down your throat and into your stomach. But it isn’t a cure-all. Charcoal doesn’t seem to help clear acid, iron, lithium, alcohols, alkali, or toxins in gasoline from the body.