You might want to reconsider that charcoal toothpaste you’ve had your eye on

Like tea, vitamins, and fad diets, toothpaste has gone the way of Instagram Sponsored—everybody’s posting about it. Specifically, we’re talking activated charcoal toothpaste. The black powder—traditionally used for less Insta-worthy activities, like treating poisoning and purifying air—is rubbed onto teeth to (supposedly) whiten them quicker and more naturally than regular toothpaste can. Your favorite Insta-celeb probably claims it’s the reason they’re sporting brighter chompers (even Drake swears by it).

When used to treat alcohol overdoses or remove pollutants from the air, activated charcoal works by absorbing toxins into its porous surface. Activated charcoal found its way into products like pre-brush powders and toothpastes with claims that it acts similarly when used on teeth, “detoxifying” and whitening teeth naturally. But according to Dr. Timothy Chase, cosmetic dentist and practicing partner at SmilesNY, long-term use of activated charcoal toothpaste actually causes irreparable harm to teeth. Furthermore, the American Dental Society does not endorse charcoal toothpaste products.

“While I have not seen tooth damage specifically caused by charcoal in my practice, cases have been documented where tooth damage, loss of enamel, tooth staining, and tongue staining have occurred,” said Dr. Chase.

Activated charcoal itself isn’t a health risk, but the abrasive nature of the powder can be damaging to your enamel, which is one of the most important parts of healthy teeth. Unlike other parts of your body, like skin or bones, enamel has no living cells and cannot repair or regrow itself. Once it’s worn away, your teeth are susceptible to major damage and discoloration. This is where activated charcoal toothpaste products can become a big problem.

In a paper published in the Journal of the American Dental Association, the authors examined 118 previously published articles on the effectiveness of activated charcoal products on teeth. Of those that qualified for the review, three reported negative outcomes (“increased caries, enamel abrasion, non-quantified negative impact”) and only one indicated no adverse oral hygiene effects from the use of charcoal. The authors also found that many online claims regarding the use of charcoal were false or unsubstantiated, “such as antibacterial, anti-fungal, antiviral, and oral detoxification, as well as potentially misleading product assertions.”

The review concluded that there is “insufficient clinical and laboratory data to substantiate the safety and efficacy claims of charcoal and charcoal-based dentifrices.” In other words, there’s no proof that using these products is safe—or that they even work.

Another study found that after brushing with charcoal toothpaste for the equivalent of three months, the tooth enamel had significantly changed compared to using a non-charcoal-based toothpaste. “Using toothpaste containing charcoal can increase the surface roughness of tooth enamel,” the study concluded.

Some activated charcoal products also claim to whiten teeth better than regular toothpaste can, and without harsh chemicals. However, Dr. Chase said, “cccording to the ADA, products containing charcoal have not been proven to whiten teeth.” In fact, he added, “The ADA cautions that using charcoal may actually thin enamel causing teeth to become yellow and weak.” 

Dentist and RealSelf contributor Dr. Victoria Veytsman also has reservations about activated charcoal toothpaste. “While there is some anecdotal evidence that it may help brighten teeth, there is no scientific evidence,” she told HG, adding that if activated charcoal tooth products are used, it should only be in moderation. And she does not recommend activated charcoal as a primary method to whiten teeth due to its potentially damaging qualities. “That said, once more studies are done I would be open to recommend this more freely,” she said.

“This stuff is legitimately amazing.”

Despite all the studies revealing the dangers of activated charcoal toothpaste, online reviews—though not vetted—show off another side of the products. Users say that after just a few uses, they see a noticeable difference in their teeth, with before-and-after photos to prove it.

Hello Activated Charcoal Toothpaste has 4.4 out of 5 stars on Amazon, with one reviewer calling it “legitimately amazing.” She goes on to say, “I used it once & could immediately see a difference. A noticeable difference! My fiancé could see a difference & he had been a skeptic!”

It’s hard not to be convinced to immediately add-to-cart, especially when the cost of these products, anywhere from $6 to $45, is cheaper than whitening at the dentist or with other at-home products.

And some professionals do endorse the use of charcoal toothpaste products, as long as you consult with your dentist before use. “As far as toothpastes go—black is the new white,” said Dr. Jon Marashi, a Los Angeles-based celebrity dentist. He believes that charcoal toothpastes can be a great addition to your teeth-care regimen, and recommended the aforementioned Hello Activated Charcoal Toothpaste. “Charcoal toothpastes can absorb and bind to compounds that stain teeth, making them brighter,” said Dr. Marashi.

If you wanted to pick up an activated charcoal toothpaste for yourself, it wouldn’t be hard. An online search or a browse down the toothpaste aisle will reveal multiple options, from your typical pastes to powders. Hello, which claims to have the #1 selling charcoal toothpaste on the market, produces a fluoride-free whitening formula that “whitens naturally,” “polishes teeth,” and “helps remove plaque.” The company’s FAQ page addresses the abrasion issue, and reads, “Our activated charcoal toothpaste is much less abrasive than charcoal powder and is well within the ISO standard for enamel safety.”

HelloGiggles reached out to find out what Hello had to say about claims that charcoal tooth products damage tooth enamel. While the company declined to comment on any specific studies, a spokesperson from the company said, “All of our toothpastes have been tested for Relative Dentin Abrasivity (RDA).”

RDA is a limit set by various medical and scientific establishments that measures the abrasivity of a product on enamel. The lower the RDA, the less abrasive the product, and products with an RDA of 250 or below are safe to use for a lifetime with limited wear to teeth. “All of Hello’s toothpastes fall well below this standard and are safe for daily use,” said the Hello rep.

Blkdiamond, which sells an activated charcoal powder that is used pre-tooth brushing, said that its product has a low RDA of 68 (about the same as Colgate toothpaste), but went on to claim that the product is not only safe on enamel, “it will actually strengthen” it. However, Dr. Chase said that “charcoal has not been proven to strengthen enamel in any study.”

When HG asked Blkdiamond to explain this claim, the company shared a paragraph from the site of another charcoal toothpaste retailer. It argues in favor of charcoal toothpaste over fluoride, which has long been used in water to strengthen teeth, stating, “The jury is still out on fluoride’s safety and what role it truly plays in your oral health.” That isn’t exactly true. Fluoride, while at times the subject of controversy, is safe to use, according to studies, and is still one of the most effective ways to prevent cavities.

The site further claims that activated charcoal detoxifies and balances the mouth’s pH levels, creating an alkalizing effect that turns the mouth into a place where bacteria cannot thrive, stopping tooth decay and cavities.

“No studies that I am aware of have stated these facts. But let’s think of this logically. Your mouth has a natural pH created by your saliva,” said Dr. Chase, explaining that when you eat acidic food, the pH of your mouth is lowered and a demineralization of enamel occurs. Soon after, though, your mouth works to rebalance itself. “Your saliva naturally returns the mouth to the correct pH and remineralizes the tooth structure,” he said. No charcoal toothpaste necessary.

And whereas no studies have confirmed that charcoal can re-harden enamel, there is one element that can—the “controversial” fluoride. “Fluoride is different because the molecule actually becomes part of the enamel structure and helps to harden the enamel,” said Dr. Chase.

Until more studies are done, use activated charcoal toothpaste with caution. There are other ways to care for your teeth that are not only dentist-approved but proven to work. If you’re looking for something plant-based or natural, try toothpaste made with neem—studies have noted its antibacterial and anti-plaque properties—or baking soda toothpaste. Most importantly, make sure you’re brushing your teeth enough and putting your dental health first.