TikTok Loves This Mouthwash Hack for "Sparkling" Teeth—But Is it Safe?

Dentists weigh in.

Close up of a woman smiling

Getty / Design by Tiana Crispino 

This may date me (a lot), but when I was young, there was no such thing as TikTok and no viral hacks to potentially help you whiten your smile and make it sparkle like the sun, all from the comfort of your own home. Instead, we had to resort to the OG version of Crest Whitestrips, which were uncomfortable to wear in their earliest incarnation—not to mention the weird chalky coating you’d get on your teeth post-whitening session. (I can still taste it.)

Obviously teeth whitening systems have improved a lot since the mid-2000s, but when it comes to at-home dental care, TikTok continues to be the place to go for beauty hacks of all shapes and sizes, including dental tips that may or may not be the best remedy for your pearly whites. The latest? Mixing a concoction of mouthwash, baking soda, and hydrogen peroxide. Users claim it gives them sparkling teeth, but is it safe? Ahead, we asked dentists to weigh in.

What Is The TikTok Teeth Whitening Hack?

It all started with one video, as viral hacks often do. The most popular video comes from user Kristen Machado, who shares an at-home teeth whitening hack that only requires a few simple, inexpensive ingredients: mouthwash (any kind), baking soda (yep, the kind you keep in the fridge or use in baking) and hydrogen peroxide, which costs just a couple bucks and is readily available at the drugstore and grocery store. “Let me let you in on a little secret,” she says. “I get complimented my teeth all the time. People are always like, ‘Where do you get them whitened?’ I don’t. Let me tell you what I do.” And voila—a viral video was born. (Similar videos have also gained traction on TikTok, including a similar DIY recipe with toothpaste in place of mouthwash, or one that skips the baking soda aspect entirely.)

For her at-home teeth whitening rinse, Kristen makes a combination of mouthwash and hydrogen peroxide and sprinkles in about a teaspoon of baking soda. She rinses with her concoction each night after brushing and says it will make your teeth “sparkle.” 

Does the Mouthwash Teeth Whitening Hack Work?

This easy DIY seems too good to be true, right? You’re not alone in thinking that; the video has over 2 million impressions and thousands of comments, including a few from dental assistants and dentists themselves. Reviews of Kristen’s method are mixed, so I decided to reach out to the pros: cosmetic dentists Dr. Alex Rubinov, based in New York City, and Dr. Daniel Rubinshtein, based in Brooklyn. Is this at-home whitening hack worth its salt (or baking soda), or is it something you should skip entirely? Surprisingly, both dentists were pretty cool with the method—with a few caveats, of course.

“​​What she’s promoting is surface level teeth whitening,” Dr. Rubinov explains. “[For example], when a toothpaste says whitening, what they mean is it removes superficial stains. No toothpaste is actually going to make a drastic enough change in relation to what bleaching solutions can do.”

“The combined ingredients do have a way of slightly brightening your teeth,” says Dr. Rubinshtein, who adds that this shouldn’t be part of your daily oral care routine. “Do not do it every day, as the acid from this mixture can irritate your gums and teeth.”

How to do the TikTok Teeth Whitening Hack

To create her at-home solution, Kristen uses three common dental care products: mouthwash (Crest Pro Health, in her case), baking soda and hydrogen peroxide, which have all been used to brighten and whiten the teeth for decades. Hydrogen peroxide is also often used at a higher strength for in-office whitening treatments.

Don't worry, combining mouthwash, baking soda and hydrogen peroxide won’t cause an at-home explosion a la Mentos in Coca-Cola, jokes Dr. Rubinov. “She took three compounds of things people use and threw them together,” he explains, adding that he approves of the mouthwash choice. “Crest Oral Health is a great mouthwash. I really like it; it’s good for gums and has a nice flavor when you rinse.” On the other hand, Dr. Rubinshtein recommends an alcohol-free mouthwash like Hello Bye Bye Bacteria Rinse ($7). 

As for peroxide, you’ll want to pay close attention to the strength; it can burn your gums, so opt for a lower, gentler percentage when you’re shopping. “The difference of the effectiveness of over-the-counter versus at-home is the percentage of hydrogen peroxide in the  solution,” shares Dr. Rubinov. “At home versions like Crest Whitestrips have less than 10%, while in-office you can be more than 20%.” 

Later in the video, Kristen shares another hack for special events: using her at-home concoction in lieu of water when brushing your teeth. Proceed with caution, advises Dr. Rubinshtein. “Do not brush your teeth every day with this solution,” he shares. “It can scratch your enamel and the acidity of this solution can erode your enamel, making your teeth sensitive and appear yellower—quite the opposite of the desired effect.”

Is the TikTok Teeth Whitening Hack Safe?

Dr. Rubinov believes that if this at-home mouthwash solution makes you more proactive about caring for your teeth, that’s the best possible outcome. “My take is, when people start using these products, they become more focused and diligent [about oral care],” Dr. Rubinov shares. “If it works for you, great! If it works for a week and then your teeth got dark again, maybe in-office will last a little longer.”

If you’re serious about a whiter smile, an in-office treatment is probably the best—and safest—avenue. “It protects the gums because you always create a barrier that protects bleaching solution from touching tissue,” explains Dr. Rubinov. “You’ll also get a higher concentration of ingredients, which leads to better results. The power of those solutions is that they can penetrate through the enamel to whiten.” 

You can also get custom fitted trays made by your dentist for at-home whitening. “You'll get a special whitening gel to apply in those trays with instructions as to how long to use them,” explains Dr. Rubinshtein. “Depending on the health and condition of your teeth, the directions will be unique to you. You can also use tried-and-true Crest Whitestrips if you're in a pinch.”

Dr. Rubiov advises skipping this hack entirely if you have tooth decay, weak enamel or other dental issues, as the chemicals in the solution could make those conditions worse. Same goes for veneers: “I recommend my patients with veneers stay 100% away from baking soda, charcoal, and other abrasive products because they can create issues on your enamel or porcelain,” Dr. Rubinov says. “There’s no regulation of particle size of baking soda as there is in toothpaste.” If you have any questions, check in with your dentist.

For a permanently whiter smile, consider veneers, which can remain stain-free for up to 15 years. Otherwise, stick to a regular oral care routine of brushing, flossing and rinsing and your teeth will thank you.  

Your Guide to Teeth Whitening

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