The value of activated charcoal comes from its adsorptive capabilities. Adsorption is the ability of a solid surface to bind and trap certain substances. It is different than absorption, which occurs when a substance is transferred into another substance. Adsorption works more like a magnet, while absorption works more like a sponge. Activated charcoal is not absorbed into the body through the digestive tract. Instead, it stays in the digestive tract and adsorbs some substances that will then be transported out in the feces, preventing them from being absorbed into the body.

Activated charcoal is often used in emergency rooms when the GI tract needs to be decontaminated, such as in cases of drug overdose or poisoning, and it is also being investigated as an adjunct treatment for those with chronic kidney disease.^{2 3 4} Not a lot of research has been done on activated charcoal outside of these few specific medical uses, but proponents have long extrapolated from these known uses and its known adsorption properties to expand on its potential benefits.

Flatulence

A long-recognized value of activated charcoal is in the reduction of excessive gas. Some studies have found it improves symptoms of gas and bloating and reduces breath hydrogen gas levels.^{5 6} Recent research has found activated charcoal to be a valuable addition to standard prep for abdominal ultrasounds, leading to better images not obstructed by excess intestinal gas.^{7 8} In the European Union, activated charcoal is recognized for this purpose and products can bear the statement, “Activated charcoal contributes to the reduction of excessive intestinal gas accumulation” on the label. For the purpose of reducing gas, a dose of one gram 30 minutes prior to a meal and one gram after the meal is recommended.⁹ Be aware that this is probably not the best solution for reducing gas long term, since taking activated charcoal with meals is likely to adsorb nutrients you need.

Detox Aid

Activated charcoal is often touted as an all-around detox miracle, and while it certainly is capable of binding to many toxins in the digestive tract, it is a little more nuanced than that. With regard to adsorbing toxins you may ingest and want to prevent from being absorbed, there is a long list of substances that activated charcoal is capable of binding to, but it is not all encompassing. In addition to chemical toxins, in vitro research suggests that activated charcoal may bind to endotoxins—toxins present in the cell walls of some bacteria—that can build up and cause endotoxemia, which promotes inflammation and in some cases can be very serious.^{10 11 12}  Activated charcoal may also bind to different mycotoxins, the toxins produced by molds, that can adversely affect many tissues and organs.^{13 14}

Another way activated charcoal can support detoxification is by binding to bile.¹⁵ When the liver does its job of detoxification, one of the ways toxins are removed from the body is in the bile. Activated charcoal can support detoxification by binding to the bile in the intestines so it can be excreted in the feces rather than being recycled back into the body.

One toxin activated charcoal is not very effective at adsorbing is alcohol.¹⁶ As for the purported benefits of taking activated charcoal to cure or prevent a hangover, some speculate that it may be binding to other chemicals that come with the alcohol, which may help to lessen the burden on the body.¹⁷

Topical Use

Activated charcoal can be spotted in body care products ranging from face masks and soap to deodorant and toothpaste. Although there is very little research on activated charcoal’s topical benefits, these products are also relying on its adsorbent properties. When used on the skin it is thought to attract dirt and oil and is probably best for oily and acne-prone skin. In some applications where it lingers on the skin for longer, like a mask, it may be irritating or too harsh for dry and sensitive skin types. Activated charcoal has been used to reduce the odor that can accompany some types of severe skin damage and loss and in air filters to remove air odors, so it seems reasonable to assume it may also reduce other odors, like underarm odor.¹⁸ As for toothpaste, charcoal is usually added to whiten teeth and the scientific jury is still out on this one.¹⁹ If you want to use a charcoal-based beauty product, be sure to check the other ingredients to make sure you’re not getting harmful chemicals, preservatives, and endocrine disruptors with your charcoal.

Other Uses

Holistic health practitioners have long recommended activated charcoal in cases of food poisoning, and it has been shown to adsorb some intestinal pathogens.^{20 21} For this purpose it should be taken at the first signs of illness and again 6 hours later.²² There is also some research to suggest it may help to reduce diarrhea associated with chemotherapy.^{23 24} Several small studies done in the 1980s found that activated charcoal lowered cholesterol in a dose dependent manner, likely due to its bile adsorbing capacity.^{25 26} Activated charcoal also has many uses outside of direct use in or on the body that benefit humans, including in water and air filters, and in industrial, agricultural, and environmental applications.

Use and Cautions

In general, activated charcoal is considered to be very safe. The most common adverse effect is constipation. Remember, activated charcoal can adsorb many of the things you want (vitamins, medications, etc.) the same as it can adsorb the things you don’t want, so be careful to take it away from medications and supplements (30 minute before or 2 hours after should suffice) and be sure to drink plenty of water. Chronic use with food may interfere with absorption of some nutrients, although a little bit to color food occasionally is probably fine. Activated charcoal is a great tool to keep in your first aid kit but it is not a substitute for emergency medical care in any case of poisoning or overdose. Finally, activated charcoal powder can be messy, so mix carefully to avoid a mess and don’t be too alarmed should you notice a black color to your stool when using it; that is normal.

References

1. Olson, K.R. (2010). Activated charcoal for acute poisoning: one toxicologist’s journey. J Med Toxicol, 6, 190-198. DOI 10.1007/s13181-010-0046-1
2. Cupisti, A., Piccoli, G. B., & Gallieni, M. (2020). Charcoal for the management of pruritus and uremic toxins in patients with chronic kidney disease. Current opinion in nephrology and hypertension, 29(1), 71–79. https://doi.org/10.1097/MNH.0000000000000567
3. Gao, Y., Wang, G., Li, Y., Lv, C., Wang, Z. (2019). Effects of activated charcoal on hyperphosphatemia and vascular calcification in Chinese patients with stage 3-4 chronic kidney disease. J Nephrol, 32(2), 265-272. doi: 10.1007/s40620-018-00571-1
4. Vaziri, N. D., Yuan, J., Khazaeli, M., Masuda, Y., Ichii, H., & Liu, S. (2013). Oral activated charcoal adsorbent (AST-120) ameliorates chronic kidney disease-induced intestinal epithelial barrier disruption. American journal of nephrology, 37(6), 518–525. https://doi.org/10.1159/000351171
5. Hall, R. G., Jr, Thompson, H., & Strother, A. (1981). Effects of orally administered activated charcoal on intestinal gas. The American journal of gastroenterology, 75(3), 192–196.
6. Jain, N. K., Patel, V. P., & Pitchumoni, C. S. (1986). Efficacy of activated charcoal in reducing intestinal gas: a double-blind clinical trial. The American journal of gastroenterology, 81(7), 532–535.
7. Jabar, A. A., Abbas, I., Mishah, N., Wazan, M., & Tomehy, M. (2020). Effect of adding a capsule with activated charcoal to abdominal ultrasound preparation on image quality. Journal of ultrasonography, 20(80), e12–e17. https://doi.org/10.15557/JoU.2020.0003
8. Maconi, G., Bolzacchini, E., Radice, E., Marzocchi, M., Badini, M., (2012). Alpha-galactosidase versus active charcoal for improving sonographic visualization of abdominal organs in patients with excessive intestinal gas. J Ultrasound, 15(4), 232-238. doi: 10.1016/j.jus.2012.04.002
9. EFSA Panel on Dietetic Produce, Nutrition and Allergies (NDA), (2011). Scientific opinion on the substantiation of the health claims related to activated charcoal and reduction of excess intestinal gas accumulation (ID 1938) and reduction of bloating (ID 1938) pursuant to Article 13(1) of Regulation (EC) no 1924/2006. EFSA Journal, 9(4), 2049. doi:10.2903/j.efsa.2011.2049. Available online: www.efsa.europa.eu/efsajournal
10. Nolan, J. P., McDevitt, J. J., Goldmann, G. S., & Bishop, C. (1975). Endotoxin binding by charged and uncharged resins. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.), 149(3), 766–770. https://doi.org/10.3181/00379727-149-38895
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    https://chriskresser.com/why-you-need-a-digital-detox/  
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14. Avantaggiato, G., Havenaar, R., & Visconti, A. (2004). Evaluation of the intestinal absorption of deoxynivalenol and nivalenol by an in vitro gastrointestinal model, and the binding efficacy of activated carbon and other adsorbent materials. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 42(5), 817–824. https://doi.org/10.1016/j.fct.2004.01.004
15. Krasopoulos, J. C., De Bari, V. A., & Needle, M. A. (1980). The adsorption of bile salts on activated carbon. Lipids, 15(5), 365–370. https://doi.org/10.1007/BF02533552
16. Hultén, B. A., Heath, A., Mellstrand, T., & Hedner, T. (1986). Does alcohol absorb to activated charcoal?. Human toxicology, 5(3), 211–212. https://doi.org/10.1177/096032718600500311
17. Axe, J. (2019, July 5). Top 10 activated charcoal uses, plus potential side effects. draxe.com. Retrieved September 8, 2022 from https://draxe.com/nutrition/activated-charcoal-uses/
18. Chakravarthi, A., Srinivas, C. R., & Mathew, A. C. (2008). Activated charcoal and baking soda to reduce odor associated with extensive blistering disorders. Indian journal of dermatology, venereology and leprology, 74(2), 122–124. https://doi.org/10.4103/0378-6323.39694
19. Brooks, J.K., Bashirelahi, N., Reynolds, M.A., (2017). Charcoal and charcoal-based dentrifices: a literature review. J Am Dental Assoc, 148(9), 661-670. https://doi.org/10.1016/j.adaj.2017.05.001
20. Naka, K., Watarai, S., Tana, Inoue, K., Kodama, Y., Oguma, K., Yasuda, T., & Kodama, H. (2001). Adsorption effect of activated charcoal on enterohemorrhagic Escherichia coli. The Journal of veterinary medical science, 63(3), 281–285. https://doi.org/10.1292/jvms.63.281
21. Bereswill, S., Mousavi, S., Weschka, D., Heimesaat, M.M., (2021). Disease-alleviating effects of peroral activated charcoal treatment in acute murine campylobacteriosis. Microorganisms, 9(7), 1424. doi: 10.3390/microorganisms9071424
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23. Michael, M., Brittain, M., Nagai, J., Feld, R., Hedley, D., Oza, A., Siu, L., & Moore, M. J. (2004). Phase II study of activated charcoal to prevent irinotecan-induced diarrhea. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 22(21), 4410–4417. https://doi.org/10.1200/JCO.2004.11.125
24. Sergio, G. C., Félix, G. M., & Luis, J. V. (2008). Activated charcoal to prevent irinotecan-induced diarrhea in children. Pediatric blood & cancer, 51(1), 49–52. https://doi.org/10.1002/pbc.21491
25. Neuvonen, P. J., Kuusisto, P., Vapaatalo, H., & Manninen, V. (1989). Activated charcoal in the treatment of hypercholesterolaemia: dose-response relationships and comparison with cholestyramine. European journal of clinical pharmacology, 37(3), 225–230. https://doi.org/10.1007/BF00679774
26. Neuvonen, P. J., Kuusisto, P., Manninen, V., Vapaatalo, H., & Miettinen, T. A. (1989). The mechanism of the hypocholesterolaemic effect of activated charcoal. European journal of clinical investigation, 19(3), 251–254. https://doi.org/10.1111/j.1365-2362.1989.tb00226.x