In recent years, activated charcoal — that’s right, the stuff commonly used in water filtration systems — has emerged as the latest “detoxifying” supplement of choice. Once primarily used in emergency rooms to treat poisonings and overdoses, otherwise healthy people are now taking activated charcoal supplements in hopes of detoxing their bodies and treating a variety of ailments, including diarrhea, gas, kidney problems, hangovers, and yellowed teeth. Like many supplements, activated charcoal is appealing because it’s easy to buy (no prescription needed), quick to take, “and it, quote-unquote, helps remove toxins from the body, which is appealing,” says Amy Shapiro, RD, the founder of Real Nutrition NYC in New York. Indeed, research shows more people are taking supplements today than a decade ago: 80 percent, compared with 65 percent in 2009, according to a 2021 consumer survey from the Council for Responsible Nutrition. (1) The top reason people cited for taking supplements was overall health and wellness. But the obsession with activated charcoal doesn’t stop with supplements; it’s being added to detox drinks, toothpaste, skin-care products, and even cocktails and ice cream. (2,3) (That said, New York banned restaurants from using activated charcoal in foods and drinks in 2018.) (4) Long story short, activated charcoal is a hot, of-the-moment ingredient and supplement. But before you jump on the bandwagon, there are a few things you should know. When ingested, activated charcoal can trap toxic substances in the gut, and thus prevent their absorption into the body. According to a 2015 review of clinical and animal studies, some charcoal preparations have a surface area nearly one-third the size of a large football field. (6) That size allows greater adsorption (attraction of atoms, ions, or molecules from a gas or liquid to a solid surface) of toxins and chemicals. (7) Once activated charcoal traps the toxins, they’re eliminated through your feces. (6)
Can Effectively Treat Poisoning and Drug Overdose in a Clinical Setting
Thanks to this ingredient’s ability to trap toxins in the gut, it can be useful in emergencies to treat drug overdoses and poisonings. And in reality, that’s the one use that MedlinePlus agrees activated charcoal is likely good for. (8) The first reported use of activated charcoal for treating poisonings happened in 1811, but the antidote became less popular over time. (6) Activated charcoal is most helpful in cases of drug overdoses and poisonings when administered immediately. According to data from 48 comparisons involving 26 drugs, volunteers who took at least 50 grams (g) of activated charcoal 30 minutes after ingesting poison reduced absorption by an average of 47 percent, per a 2005 position paper. Yet most of the comparisons involved small sample sizes, usually between 6 and 10 volunteers. (9) In addition, many people don’t show symptoms until at least two hours after ingesting a toxin, which means most of the toxin has likely already been absorbed or moved into the intestine, according to a 2002 review. Still, if digestion has slowed, activated charcoal may help reduce the final amount absorbed. The same review suggests that 50 g of activated charcoal taken three hours after poisoning can reduce absorption by an average of 21 percent. Unfortunately, this review was published in 2002, and the conclusions may no longer apply. (10) But activated charcoal may not be effective in all cases of poisoning and overdose, and should only be used on a case-by-case basis. (6) And activated charcoal is ineffective for poisonings involving alkalis, strong acids, petroleum products, or alcohols. (11)
May Help Support Kidney Function
Activated charcoal may help eliminate waste products like urea from the kidneys, and thus benefit people with chronic kidney disease, who can’t remove these waste products as effectively as people with healthy kidneys, according to a 2015 review. (14) In one very small 2010 study, older people with end-stage renal disease saw a significant decrease in blood urea and creatinine levels after taking 30 g of activated charcoal per day in combination with a low-protein diet for 10 months. (It’s worth noting that this study involved only nine participants, so don’t take these findings to heart just yet.) (15) If you have kidney disease, your healthcare team may recommend a low-protein diet. (16) Again, more research is needed before doctors recommend activated charcoal to support kidney function.
May Help Reduce Excessive Gas
Research suggests activated charcoal may offer relief from excessive gas. A small 2003 study found that activated charcoal effectively reduced gas and bloating in men with and without excessive gas. (17) A 2017 observational study noted that a combination of simethicone (Alka-Seltzer is one brand) and activated charcoal helped reduce gas by 25 percent in people with small intestinal bowel overgrowth (SIBO) after 10 days. SIBO is associated with greater gas production. Nevertheless, participants who took the antibiotic metronidazole (Flagyl) saw even better results, with a 67 percent reduction in gas. One limitation of this study, though, is that participants self-reported their gas incidents in a three-day diary before and after treatment, so it’s hard to know if incidents were accurately reported — not to mention that three days is a short period of time. (18) A panel of the European Food Safety Authority ruled that there’s enough evidence to support the use of activated charcoal for excessive gas, and recommends taking at least 1 g about 30 minutes before a meal, as well as 1 g after the meal. The U.S. Food and Drug Administration (FDA) hasn’t made the same recommendation, and it’s important to note that the FDA does not regulate any supplement, including activated charcoal, the same way it does medical drugs. (19,20)
May Help Treat and Prevent Diarrhea
Because activated charcoal traps toxins in the gut, it may work to prevent diarrhea-causing bacteria and drugs from being absorbed into the body. In fact, the authors of a 2017 review state that activated charcoal is a suitable treatment option for diarrhea, particularly because the supplement has relatively few side effects compared with other antidiarrheal treatments. (21) That said, the Mayo Clinic states that activated charcoal has not been shown to be effective in relieving diarrhea. More research is needed to confirm whether activated charcoal can in fact play a role in treating and preventing diarrhea. (11)
May Affect Gut Health
One of the risks of taking activated charcoal outside of a clinical setting is that, in the process of trapping and eliminating “toxins,” the supplement may also remove important nutrients from the digestive tract. That could harm the balance of gut bacteria, posing health risks, noted a 2015 review. Alternatively, it may reduce or prevent the absorption of medications, Bochi warns. (23) What’s more, activated charcoal can cause some unpleasant side effects, such as nausea, constipation, and vomiting, Bochi adds.
May Harm Your Teeth
In addition to the risks of ingesting activated charcoal, there are also risks associated with using it to clean or whiten your teeth. Supposedly, activated charcoal has antibacterial, antifungal, antiviral, and oral detoxification properties, but a 2017 review reveals there’s not enough evidence to substantiate these claims. What’s more, three of the studies included in the review reported negative outcomes, such as increased caries and enamel abrasion, which can contribute to cavities. Authors advise dentists to warn patients about using charcoal and charcoal-based teeth products. (24)
More Studies Needed on How It Affects the Skin
Beauty companies are also adding activated charcoal to skin-care products. In a 2017 paper, researchers who incorporated activated charcoal into a skin-care formula claim the substance drew bacteria, dirt, and other microparticles to the surface of the skin, helping fight acne. (25) But no research has been done in humans to test these statements, so it’s unknown whether activated charcoal offers any skin-care benefits. The risks are also unknown.
Effects Are Unclear When Charcoal Is Ingested for Hangovers or Other Issues
There’s no research to substantiate the benefits of adding activated charcoal to foods, either. Black ice cream and hamburger buns may look cool, but it’s doubtful whether all that activated charcoal is actually doing your body any good. And, by the way, if you’re using activated charcoal to prevent or treat a hangover, the effects in that case are also unclear. Most of the research on this topic was published decades ago, and the U.S. National Library of Medicine notes that the body doesn’t appear to trap activated charcoal well, meaning it’s unlikely a panacea for your aches and pains before or after an indulgent night. (8) If you’d like to try activated charcoal, you should do so under the supervision of a medical professional, especially if you’re already taking other medications. Your doctor can work with you to find the right dosage and frequency if the supplement is the right fit for your health goals. And although activated charcoal has not been reported to cause birth defects or other health problems in babies, per the Mayo Clinic, play it safe and check with your doctor before taking activated charcoal if you’re pregnant or breastfeeding. (11)
