Activated charcoal is everywhere: This black powder is turning up in supplements, cocktails, smoothies, deodorants, face masks, and more, with promises to cleanse your insides, reduce body odor and bad breath, stop gas and bloating, brighten skin, clear acne, and even whiten teeth.

Activated charcoal is similar to the stuff you use when you barbecue, but it's super-heated into an extremely porous substance. In this form, it has been used in the emergency room as an antidote for overdoses on meds such as acetaminophen and antidepressants.

But is activated charcoal beneficial outside of the ER? Here's what you should know about the different uses of activated charcoal, and how much science there is to support each claim:

Activated Charcoal in the ER

In the case of a drug overdose, ER doctors sometimes feed an activated charcoal paste to patients as a drink or via a feeding tube. If done quickly (ideally within minutes but up to an hour or two after ingestion while the drug is still in the stomach), the porousness of activated charcoal traps the toxins, preventing the body from absorbing them.

More than 50 published studies have examined the use of activated charcoal in ERs. But its efficacy even there is limited: The American Academy of Clinical Toxicology emphasizes that it should not be used routinely for poisoned patients but only for certain types of overdoses and only if it can be administered within an hour of ingestion.

In recent years, people have tried to translate the very limited success of activated charcoal in the ER to their everyday lives, assuming that if it can adhere to and remove certain drugs in the emergency room, it can sop up all kinds of toxins, making an already healthy person even healthier. 

But this logical leap is not based in science, explains Lisa Sasson, M.S., R.D., clinical associate professor of nutrition at New York University. “I don't think that was ever the intent" of activated charcoal, she says.

As a Stomach Aid, It Might Work

Two small studies performed in the 1980s and 1990s looked at whether activated-charcoal supplements could reduce intestinal gas, and they came to opposite conclusions—one study (with about 100 people) said they worked; the other (with only five people) said they didn't.

A more recent study of 276 patients suffering from indigestion found that activated charcoal in combination with the mineral magnesium oxide helps with indigestion. This suggests that there is indeed a bit of science backing up the use of activated charcoal for gastrointestinal problems.

None of these studies has been replicated or confirmed in larger groups, however, and Shana Kusin, M.D., assistant professor in the Department of Emergency Medicine at Oregon Health & Science University’s Hospital & Health Systems, cautions that based on its use in the ER, “there's actually a belief among physicians that charcoal can make people vomit or have diarrhea.”

Indeed, some studies have found that vomiting occurs in as many as 20 percent of patients given activated charcoal, so using it to treat an upset stomach could backfire.

Can It Control Body Odor, Fight Acne, and Whiten Teeth?

Activated charcoal is being mixed into toothpastes, soaps, and deodorants to freshen breath, reduce body odor, clear up acne, and whiten teeth. But there are very few studies scrutinizing whether these products can deliver on any of these claims.

There are no published studies on charcoal used for whitening, for example; one unpublished experiment presented at a dentistry conference noted that “fine black charcoal powder” could actually become embedded in cracks or small holes in the teeth—doing the opposite of whitening.

There are also no studies we found examining whether activated charcoal, particularly taken orally, might work to reduce general odors (either as a breath freshener or deodorant). There have been studies showing that activated charcoal dressings can tamp down foul stenches from skin wounds and ulcers. But if you have an infected wound or ulcer, you should seek treatment or advice from a doctor before trying any form of activated charcoal.

Activated-charcoal face washes and creams often have product labels promising to clear up acne and clarify the skin by removing toxins from your pores. But there's no published evidence, says Ranella Hirsch, M.D., a dermatologist at Skincare Doctors in Boston, to suggest this works, either. 

Will a Charcoal Pill 'Detox' You?

According to Kusin and Sasson, the body already has organs such as the kidneys and liver to filter out impurities. What's more, they say, activated charcoal only removes toxins in the stomach—it doesn’t purify your blood.

Says Kusin: “I don’t see any true health benefit of popping charcoal supplement pills."

The amount of charcoal administered in the ER for drug overdoses—about 25 to 50 grams for an adult—is roughly 100 to 200 times the amount you’d get in a typical 250-milligram supplement, Kusin explains. One or two charcoal pills, or a pinch of powder in your smoothie, won't “detoxify” anything, especially because its limited function relies so much on being used almost immediately after a poison is ingested. 

Though charcoal in such small doses has no known safety risks, it's also difficult to be certain exactly what you're getting when you buy any supplement or natural product. As Consumer Reports has reported previously, supplements are regulated much more loosely than FDA-approved drugs, so something like an activated charcoal supplement or smoothie doesn't necessarily contain what is advertised on the label.  

Duffy MacKay, N.D., senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, a supplement industry group, says that the general lack of scientific proof supporting popular uses of activated charcoal is not uncommon with popular home remedies.

"People like to use mint after a meal to help with digestion or to soothe their stomach," MacKay says. "Is that proven to work through clinical trials? No. Are there a lot of people who enjoy the way it makes them feel? Yes. Is it appropriate? Well, consumers want these options."

What to Do Instead

Activated charcoal is not a magic health bullet, but there are some things you can do or take instead.

To reduce gas and bloating: Stay away from sugar-free gums with artificial sweeteners such as sorbitol and manitol, advises Sasson, and stick to a whole-food, plant-based diet.

To whiten teeth: Try at-home whitening kits that contain hydrogen peroxide or carbamide peroxide, and ask your dentist about in-office whitening procedures that can reduce more serious discoloration. Swish water in your mouth after drinking beverages that tend to stain teeth, such as coffee and tea, and skip colas altogether.

To clear skin: Over-the-counter and prescription acne treatments can help reduce blackheads, whiteheads, and pimples. If your skin is particularly oily, Hirsch suggests bars and peels that have active ingredients such as retinols and alpha hydroxy acids. If OTC products don’t work, call your doctor or a dermatologist. She might prescribe prescription topical creams and gels, or oral medications, or other treatments such as laser or light therapy that can help.

To "detox" (i.e. remove waste from the body naturally): Drink plenty of water and eat a high-fiber diet, Sasson says.