Activated charcoal is everywhere. Touted in alternative health circles as a versatile treatment for almost anything that ails you, its proponents claim that it clears up your acne, treats inflammation caused by "toxic mold," draws out the venom from a snake bite, eases a hangover, halts your farts, removes "toxins" from your body, and brightens your pearly whites.
But there's little to no evidence for these claims. Though charcoal has a very long history as a folk remedy—ancient Egyptians used it as a treatment for "odorous vapors from putrefying wounds"—for the past century or so, its medical use has primarily been in emergency rooms to treat overdose and poisoning cases. In most cases there just aren't any clinical studies to test its efficacy for any other use. Not only that, but experts who spoke with Mental Floss caution that these treatments might come with added risks, too.
WHAT IS "ACTIVATED CHARCOAL"?
Activated charcoal isn't quite the same thing as the briquettes you use in your grill. Though they're both made of residue left from burning carbon-rich organic materials like wood, peat, or coconut shells, activated charcoal is oxygenated, which makes it far more porous. To activate the charcoal, manufacturers use steam or hot air to erode its internal surface [PDF], which increases the outside surface area along with its adsorption rate—the capacity to bind materials to a surface. Because of those adsorption abilities, charcoal has earned a reputation as a kind of bodily super-cleanser.
When you ingest activated charcoal, it works as a "gastrointestinal decontaminant," attracting various chemicals from your stomach and digestive tract, and then eliminating them from the body. That's why it's so helpful in cases of poisoning or drug overdose: It adsorbs the dangerous substance so it doesn't enter your bloodstream, then simply passes right on through—and out of—your system.
FROM E.R. TO GOOP
Activated charcoal had been popular in certain health food circles for years when, in late 2014, Gwyneth Paltrow's website Goop featured a "charcoal lemonade" sold by a Californian juice bar on a list of the best juice cleanses for "a good old-fashioned detox." Today, the substance can be found in everything from facial masks and odor-dampening comforters to a wide range of food and drink: Chefs are using activated charcoal to create pitch-black cakes, cocktails, pizza crust, and ice cream that's taking Instagram by storm.
The tiny bit of activated charcoal in the occasional cocktail probably won't do any damage—but it's not a good idea to take the substance on a regular basis, according to Rachele Pojednic, a professor of nutrition at Simmons College. "When you ingest it, you can't target what it's going to interact with," she says, "so if you’re on certain medications, you need to be really careful."
Some have never been on board with the stuff, including the FDA and the New York City Department of Health and Mental Hygiene, which recently started enforcing in restaurants a long-standing ban on activated charcoal. The agency—following FDA guidelines—considers it an "adulterated food."
IN CASE OF POISONING …
"There's really no data to show that [activated charcoal] is going to do anything other than remove some pretty high-level ingested toxins" like the ones found in cases of poisoning or overdose, Pojednic says.
It's also dubious that activated charcoal can cure a hangover, as some alternative health practitioners recommend. "You feel a hangover because you're really dehydrated," she tells Mental Floss. "There's nothing in your system that needs to be extracted." While you might feel better after taking it, Pojednic says that's most likely because your hangover went away over time.
There are some risks associated with ingesting activated charcoal, too. Thanks to its adsorption abilities, charcoal can also take out all of the good chemicals in your system, including nutrients and the active ingredients in certain medications (like antidepressants) if taken around the same time.
BRUSH YOUR TEETH BLACK?
One of the most common products you'll find activated charcoal in is toothpaste; its advocates claim it whitens teeth. About a year ago, John Brooks, DDS, a dentist and researcher at the University of Maryland School of Dentistry, found himself getting questions from clinicians and students wondering what to tell their patients about activated charcoal toothpaste. He and two other professors reviewed the scientific literature and found that there's little evidence to support the claims of charcoal toothpastes because they haven't been tested. Brooks tells Mental Floss, "None of these charcoal toothpastes have undergone the rigors of scientific testing."
And, again, there are potential risks. While it's possible these toothpastes could whiten your teeth in the short term, they're so highly abrasive that they're likely to remove the enamel from your teeth too, which means your teeth won't stay white for long. Brooks also worries about patients regularly swishing known carcinogens—like silica and bentonite clay, which some charcoal toothpastes contain—around in their mouths. Moreover, he says, charcoal could potentially interfere with beneficial toothpaste ingredients, like fluoride.
IN THEORY, IT COULD HELP YOUR SKIN
The one cosmetic benefit of activated charcoal might be found in skincare products—maybe. As chemist Michelle Wong writes, "There isn't any good data on whether or not it works, but theoretically, it could work." It's possible activated charcoal's adsorption abilities could reach into your pores, pulling out the dirt and oils that get trapped there. But these products have not been rigorously tested, so we can't be certain about their efficacy. Wong also points out that activated charcoal typically takes several hours to have an effect, whereas most charcoal skincare products are applied for mere minutes.
The activated charcoal trend seems to be holding strong, despite the lack of evidence for its health claims. So eat that pitch-black ice cream every once in a while if you like, but don't count on it to improve your health.