Activated charcoal is a fine, odorless, black powder that is often used in emergency rooms to treat overdoses. It is made by heating carbon-rich materials, such as wood, peat, coconut shells, or sawdust, to very high temperatures, which strips the charcoal of previously absorbed molecules and frees up bonding sites again. This process also reduces the size of the pores in the charcoal and makes more holes in each molecule, increasing its overall surface area. Activated charcoal is commonly used to treat poisoning by trapping drugs and other types of chemicals to stop poisoning. It is also used for high cholesterol, hangovers, and upset stomach, but there is no strong scientific evidence to support most of these uses. Activated charcoal reduces absorption of substances in the stomach and intestines, so taking activated charcoal along with birth control pills can decrease how much of the birth control pills the body absorbs. It is important to note that activated charcoal should be used under the guidance of a healthcare provider along with standard treatments for poisoning. Charcoal tablets or capsules are sometimes used to absorb gases in the stomach that cause stomach gas, but they should not be used to treat poisonings or overdose.