Fact Sheets

Activated Charcoal

January 11, 2017   /
Crystal Petrello, MS, RDN, LD

Scientific name: Carbon

Also known as: Activated carbon, vegetable charcoal/carbon

Charcoal is most commonly sourced from organic substances such as peat, coal, wood, coconut shells, or petroleum. It is activated by heating the charcoal to a high temperature in the presence of an oxidizing gas (eg, steam, gas with activating agents, or carbon dioxide). This increases the surface area of the charcoal to at least 900 meter per squared gram. The surface area must be at least this surface area to meet United States pharmacopeia (USP) standards. The surface area allows for “pores” to be created in order to trap chemicals when ingested. 

Likely safe: Orally when used short term. When used to treat acute poisonings it should only be used in a health care facility.

Possibly safe: When pregnant and lactating when used orally in the short term (due to acute poisoning).

Likely effective when used as part of treatment for acute poisonings such as when used after gastric lavage (stomach pumping). But it is not useful in some cases, including poisoning from cyanide, lithium, alcohol, and iron tablets. 
Insufficient reliable evidence: Cholestasis, flatulence, high cholesterol

People are using for

  • Whitening teeth by brushing teeth with activated charcoal
  • To “detox” 
  • Help ease food poisoning
  • Topically as a poultice to aid in bug bites/stings 
    • Poultice is used by means of holding substance in place with cloth

Interactions with

  • Alcohol
  • May reduce absorption of micronutrients
  • May interact with antibacterial medications, cholesterol-lowering herbs and supplements, and herbs and supplements that block acetylcholine
  • May reduce or prevent the absorption of certain drugs. This may include drugs such as acetaminophen, digoxin, theophylline, and tricyclic antidepressants

Adverse actions

  • Orally it can cause constipation and black stools possibly leading to gastrointestinal (GI) obstruction and pulmonary aspiration.
  • When given with cathartics (medications that increase the rate of defecation) the combination can cause electrolyte imbalances and metabolic acidosis. 

References and recommended readings
Activated charcoal. WebMD website. http://www.webmd.com/vitamins-and-supplements/activated-charcoal-uses-risks. Reviewed December 26, 2014. Accessed May 18, 2015.

Activated charcoal: Bottom line monograph. Natural Medicine Journal. 2013;5(8). http://naturalmedicinejournal.com/journal/2013-08/activated-charcoal-bottom-line-monograph.  Accessed May 18, 2015.