evidence: Activated charcoal is a special form of carbon that’s effective at binding to other substances (adsorption). It’s used in emergency rooms to treat some cases of poisoning. When the charcoal comes into physical contact with the poison in the gastrointestinal tract, the charcoal adsorbs the poison. This reduces the amount of poison absorbed by the body and thus reduces the poison’s effect on the body. However, activated charcoal can’t reverse the effects of poison already absorbed and can’t act as a substitute for medical attention.