Activated charcoal is a highly reactive carbon compound that absorbs toxins and gases in the digestive tract. It is composed of microscopic chambers and cavities that result in a significant surface area which easily captures and traps most toxin substances with larger molecules. It is for this reason that charcoal is often used in air and water purifiers. Veterinarians also use activated charcoal to treat food and chemical poisonings in dogs, particularly when they have ingested too much chocolate.

This carbon compound works through adsorption. Foreign molecules are attracted and become lodged in the surface of the compound, like a lint brush. This process differs from absorption, where material passes through the surface and is assimilated, like water into a paper towel.