context: Activated charcoal is sometimes used to help treat a drug overdose or a poisoning. When you take activated charcoal, drugs and toxins can bind to it. This helps rid the body of unwanted substances. Charcoal is made from coal, wood, or other substances. It becomes "activated charcoal" when high temperatures combine with a gas or activating agent to expand its surface area. People take activated charcoal to manage a poisoning or overdose. When used along with other treatments, activated charcoal may be effective for an acute poisoning. But it is NOT useful in some cases, including poisoning from: Cyanide Lithium Alcohol Iron tablets It also is not used to treat poisons such as strong acids or bases. With a poisoning, don't guess about the right thing to do. Call your local poison control center immediately. And get to an emergency room. You need to use activated charcoal as soon as possible if it is recommended. Other less studied uses of activated charcoal include: Treat a condition of pregnancy in which the normal flow of bile is affected (cholestasis) Prevent gas Reduce high cholesterol Prevent a hangover Early research about using activated charcoal to treat cholestasis of pregnancy is very limited. More studies are needed to prove its safety and effectiveness. It's not clear whether activated charcoal helps improve gas and cholesterol. That's because the research results so far have been inconsistent. As for hangover remedies with activated charcoal, there isn't really any evidence that it works. The activated charcoal that is used to treat a poisoning is a powder that is mixed with a liquid. Once mixed, it can be given as a drink or through a tube that has been placed through the mouth and into the stomach. Activated charcoal is also available in tablet or capsule forms to treat gas. This form is not used to treat a poisoning. Activated charcoal is a manufactured product. You cannot find it naturally in foods. When used to treat a poisoning or overdose, activated charcoal is usually safe, but it needs to be administered only in a health care facility. Side effects are more likely when it is used on a long-term basis to treat conditions like excess gas. Side effects. When you take it by mouth, activated charcoal can cause: Black stools Black tongue Vomiting or diarrhea Constipation In more serious cases, it can cause gastrointestinal blockages. Risks. Do not combine activated charcoal with drugs used for constipation (cathartics such as sorbitol or magnesium citrate). This can cause electrolyte imbalances and other problems. Interactions. Activated charcoal may reduce or prevent the absorption of certain drugs. This may include drugs such as: Acetaminophen Digoxin Theophylline Tricyclic antidepressants Do not use activated charcoal as a supplement if you take these medications. Activated charcoal may also reduce absorption of certain nutrients. The U. S. Food and Drug Administration ( FDA) does regulate dietary supplements; however, it treats them like foods rather than medications. Unlike drug manufacturers, the makers of supplements don't have to show their products are safe or effective before selling them on the market. Be sure to tell your doctor about any supplement you're taking, even if it's natural. That way, your doctor can check on any potential side effects or interactions with medications, foods, or other herbs and supplements. He or she can let you know if the supplement might increase your risks.