Activated charcoal is made from peat (decomposed vegetable matter) and coconuts, which are specially treated at high temperature. When seen under a microscope, activated charcoal has many small chambers that create an extensive surface area. These chambers are able to trap the molecules of most toxic substances. This is why charcoal is widely used in air and water filters.
Charcoal works by a process called adsorption. This means that charcoal collects substances on the surface. (This is different from absorption, which means to incorporate or assimilate a substance). Charcoal is an inert material, which passes through the intestines without being absorbed into the body. It absorbs gases and thereby helps relieve flatulence, fullness and bloating.