Charcoal (activated coal) is a commonly used medication. Traditionally, it is used in various digestive disorders, typically against diarrhea. It may be also administered in case of intoxications, but its effect in such indication is largely limited.


Activated charcoal has a large active molecular surface and it is able to bind a wide range of pollutants and toxic substances. When bound by the charcoal, the toxic substances can not be absorbed by the digestive tract. The charcoal is administered either in form of tablets or water-soluble powder.


In daily life, charcoal tablets are used in cases of indigestion, usually in infectious diarrheal diseases and irritable bowel syndrome. In acute medicine, activated charcoal is used during stomach pumping, which is performed in intoxications. After the gastric content is flushed out by a tube introduced into the stomach, charcoal water solution is applied into the stomach to bind any remaining pollutants.


Activated carbon, however, does not absorb a variety of substances. It is absolutely ineffective in alcohol, methanol and ethylene glycol poisoning. We must also take into account that charcoal colors mucous membranes of the digestive tract to black and it also causes appearance of black stool. For this reason, we should not use charcoal when we plan to perform endoscopic examination (colonoscopy). When using other mediations, it is advisable to wait at least two hours after taking the charcoal. Otherwise, there is a risk that the activated carbon molecules bind the active drug substance and prevent their proper absorption.


Charcoal is commonly used in case of acute diarrhea and it is also administered in acute intoxications. However, its effects are not miraculous and we should use it rather as a support therapy.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources