These black toothpastes promise whiter teeth, but they can cause lasting damage to your smile.

Until relatively recently, I associated the word "charcoal" exclusively with backyard barbecues where '80s rock music blared and a bunch of dads stood around in white crew socks talking about football. You can imagine my surprise when I opened Instagram one casual afternoon and saw a photo of a girl beaming with what looked like tar smeared all over her smile. 

Oh gosh, I remember thinking, why does she have tar on her teeth?!

Needless to say, it wasn't tar -- it was charcoal, and after clicking down the hashtag rabbit hole, I realized it was activated charcoal, or a version of the cookout essential that purportedly boasts some serious cleaning powers. Those supposed powers come from the substance's ability to latch onto everything it contacts, including dirt, toxins, chemicals, drugs and bacteria. 

Read: The best electric toothbrushes in 2019 for whiter teeth and a healthier mouth   

Charcoal toothpaste started as a sort of "boutique" trend that small wellness brands supported, but even big brand names like Colgate and Crest now have their own charcoal toothpaste products. 

Because of that, activated charcoal has made its way into everything from face masks to supplements to lemonade. Yes, lemonade. The kind you drink. 

If people slather it on their faces and ingest it, I guess it shouldn't come as a surprise that people also brush with it. But will this magical internet elixir really result in brighter teeth? Here's what we know. 

Let's start with a reminder about what regular charcoal is: a form of carbon, usually derived from wood, which is heated until there's no water or other compounds left. Good charcoal is almost 100% carbon, and it most often presents as the stone-like product used for grilling.  

Activated charcoal is produced in a similar way, but with a few key differences. The process also involves heating several different carbon-rich materials, which can include wood, but also other materials such as peat, sugar, coconut shells, coal or sawdust. 

Activated charcoal is heated to even higher temperatures than regular charcoal, which makes it more absorbent, allowing it to bind very easily to other substances. It's also usually found as a fine powder, rather than the hard blocks you throw on your grill. 

Essentially, activated charcoal is a form of carbon that's gone through additional treatment to make it super porous. That high porosity makes activated charcoal a cleaning powerhouse -- so powerful that it's used to strip poison from people's bodies. And that's nothing new: Apparently, doctors have been using activated charcoal to save lives for a really, really long time, and it's on the World Health Organization's list of essential medicines. 

Ads for charcoal toothpaste claim you'll get a noticeably whiter smile after just one use, but there's no evidence to support that. 

Because of its super absorbent properties, activated charcoal is thought to detoxify your mouth and super-clean your teeth by latching onto bacteria, tartar, food residue and stains, and stripping them all from your mouth. 

The supposed result? A cleaner mouth and brighter, whiter teeth. 

Keep in mind that the evidence on charcoal toothpaste itself is limited -- even called insufficient by some scientists -- so no one can yet definitely claim that charcoal toothpaste whitens or cleans your teeth better than any other toothpaste. In fact, one study compared activated charcoal toothpaste to other toothpastes and found that the charcoal brand performed no better than the others. 

There's plenty of anecdotal claims that charcoal toothpaste prevents cavities or otherwise promotes better oral health, but again, there's no sound scientific evidence to support those claims. 

Considering the fact that doctors and scientists have used activated charcoal for medicinal purposes for centuries, it's probably safe to say that you can use activated charcoal toothpaste without any serious adverse effects. 

The super-high heat used to make activated charcoal eliminates any harmful substances that may have been present in the original substance (wood, coconut shells, etc). 

Keep in mind one potential side effect: Charcoal is abrasive, so prolonged or excessive use could damage the enamel on your teeth. 

You can also find charcoal whitening powders, like this one from Active Wow.

Activated charcoal is extremely porous and absorbent, so it definitely makes sense to think it can lift dirt, stains and tartar from your teeth for a whiter smile. For now, though, the evidence is limited, and there's no proof that charcoal toothpaste actually does the things that the Internet claims it does. 

As with all products that claim to be miracle cures, take those claims with a grain of salt. Or in this case, a lump of charcoal. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.

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