If you’ve spent any time on TikTok, you’ve probably seen an influencer make an ad for LED teeth-whitening kits — the little mouth-guard-shaped devices that you pop into your mouth and that claim to brighten your teeth in just ten minutes. When I first started writing about teeth whiteners and whitening kits, they were mostly manufactured by Snow and Auraglow, but in the last couple of years, more reputable brands, like Crest and Colgate, have gotten into the game. The thing is, I’ve never been recommended a teeth-whitening kit with an LED light by the dozens of dentists I’ve spoken to in my reporting — so I wanted to understand how LED teeth-whitening kits work and if they actually do anything.
First, what exactly are LED teeth whiteners? These blue LED mouthpieces are placed over teeth after applying whitening gel. To break it down simply, the lights heat up the gel’s peroxide and act as an accelerator. In theory, the light helps the gel break up more stains faster. Several LED teeth-whitening kits make these claims, with some even saying their devices are similar to dentist-office whitening.
However, over-the-counter LED teeth-whitening kits are very different from the procedures done at a doctor’s office. “It’s important to look at the overall caliber, intensity, and quality of the LED light,” Boca Studio founder and orthodontist Dr. Erin Fraundorf says, adding that at-home devices are significantly lower power and quality than the professional ones. I searched online for information on some at-home LED devices and found that they’re usually powered with less than one watt. The LED devices at dental offices, on the other hand, are typically powered with around 40 to 60 watts. “You might as well be putting your phone flashlight up to your teeth if you’re using an at-home LED light. They’re fairly pointless unless you just want to post a cool Instagram selfie,” Fraundorf says.
At-home LED teeth-whitening kits may deliver results. But the whitening you see is a result of the gel, not the light. “There is not enough data to show definitively that the LED offers a significant improvement over just using a tray with the gel,” says cosmetic dentist Dr. Jon Marashi. And, when I reached out to the American Dental Association (ADA), a representative sent me an official statement that reads: “A systematic review and network meta-analysis showed no difference in the outcomes after whitening treatments either with or without light activation.” A Colgate article references a study from the Journal of Conservative Dentistry with evidence that gel and use of an LED was more effective than gel alone. But the gel used in the study contains at least 37 percent hydrogen peroxide — a percentage used in professional settings only. (At-home gels are made with around 15 percent hydrogen peroxide.) So while there’s evidence out there that LED lights are beneficial for teeth whitening, it seems to be limited to those found at the dentist’s office.
Sensitivity is a very common side effect of teeth whitening — both at home and in a doctor’s office. While some LED kits claim they cause less sensitivity than other whitening methods, I wasn’t able to find any studies supporting this. None of the dentists I spoke to backed up the claim either. Most dentists said sensitivity is most likely caused by the whitening gel’s active ingredients and not the light itself.
LED whiteners may not actually work, but don’t underestimate the power of a fun, trendy gadget. Dr. Mandy Kouroshnia, dentist and owner of CityZen Dental, told me that LEDs do help people stick to their whitening routines. She’s observed that her patients who use LED kits are more consistent. “I think there’s this little psychological thing that happens when you have the light plus the gel. It makes you feel like you’re doing dual things and it’s going to work better,” she says, adding that consistency is key for teeth whiteners to work. “I think that’s why patients say, ‘Oh, it works great.’ But if you compare them with patients who just use simple peroxide products without any light — and the amount of compliance is the same — you’re going to have the same results.”
Regular gel trays and strips are your best bet for whitening efficacy — just be consistent and wear them for the recommended amount of time. (Check out my guide to the best at-home teeth-whitening kits if you want to see some options that work.) But if you’re the type of person who likes a little drama, a kit with LED might make you whiten more consistently. They’re okay to try, but know you’re probably not getting a real boost in results.
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