Convincing consumers to use a LED device should be simple, given how straightforward it is in theory. In practice, education is a slow and challenging process. “It looks too good to be true,” says Lotti Tyson, the brand director at Déesse Pro, which sells a $1,900 mask created in collaboration with aesthetician Shani Darden. “You're like, ‘well, hang on, this thing has very few contraindications, it doesn't cause any sensitivity.’ That does sound too good to be true.”

While red light is still, in comparison with other wavelengths, the most researched for its effects on skin, others—like near-infrared at approximately 800 nanometers, or yellow light near 590—have been incorporated into new masks and do have some official, if scarce, literature to back them up. (A new LED mask by the brand Sunlighten also incorporates green light to serve as a “full-face wrinkle treatment and mood booster,” according to an email sent to editors. None of the dermatologists we spoke to for this story have seen clinical evidence of green light being effective for mood-boosting or wrinkle-treating, but early studies show it can help reduce headaches.) A few independent studies have shown that near-infrared light—as opposed to far-infared light, which can be used in medical settings to treat inflammatory and cardiovascular conditions—penetrates the skin more deeply than other wavelengths to help with wound healing. At the Consumer Electronics Show in Las Vegas earlier this month, L’Oréal Paris announced that it will launch a mask that incorporates both near-infrared and red light sometime in 2027. Yellow light, like red, has shown some promise in small studies for treating redness and rosacea, as well as soothing inflammation following in-office treatments like lasers.

Déesse says that when they looked into incorporating blue light into their devices, their own research found that it killed acne-causing bacteria at around 415 nanometers, but at 420 it killed skin cells instead. “At 420, you may cause hyperpigmentation in certain skin types, but you're certainly not killing any bacteria,” Tyson says, adding that “the crappy [masks] on TikTok” can clock in at around 450-plus nanometers. Systematic studies of blue light show that bacteria is killed between 405 and 420 nanometers; while a 2021 study out of the University of Lodz observed hyperpigmentation in skin with blue light between 423 and 450 nanometers, though much of it wasn’t permanent, researchers said. If you actually want to verify an LED device’s wavelength claims you would have to purchase a spectroradiometer, which could run you upwards of $2,200 if it covers a wide enough wavelength to be effective (and would be an impressive level of consumer due diligence).

As the FDA is unlikely to create specific guidelines around LED devices any time soon, the burden falls on companies themselves to prove their worth. Some will rely on expensive clinical trials, while others will invest in equally expensive PR campaigns, leaving us—as always!—to figure out the truth for ourselves. “I’ve reached out to several different companies asking them if they're interested in doing any clinical trials or research,” says Jared Jagdeo, MD, associate professor of dermatology and director of the Center for Photomedicine at SUNY Downstate Health Sciences University. “And because of the ease of selling these devices without the need for clinical trials, [companies] oftentimes forgo investing in that and focus their energies on marketing [instead].” That said, the most valuable things to look for are, in order of importance: Third-party clinical trials of that exact device involving at least five subjects (though the more the better, says Dr. Jagdeo) that are published on a brand’s website (and ideally in a peer-reviewed journal); independent academic research on the specific wavelength employed in the device (which should be clearly listed in the product description); and firsthand reviews from people you know in real life (online customer reviews are, unfortunately, not always to be trusted). Omnilux, which has a scientific advisory board that includes Dr. Jagdeo, has been publishing its LED research in peer-reviewed journals since the company’s inception. Some brands, like Déesse, share before-and-after imagery of people who’ve used their devices consistently over weeks or months. Always look for consistent lighting and positioning in these transformation photos, because the wow factor can be misleading.

So let’s review: red light, yellow light, green light, blue light, LED, nanometers, near-infrared, far-infrared, 510 (k). You’ve got all that? Neither do we. It seems there is no clear-cut victor in the Red Light Wars. (Kind of like Star Wars in the early aughts: mired in confusion and plot chaos.). Do they work? Maaaaybe. (Just don’t slack off.) Are they safe? Probably, but depends. Are they worth the money? See questions one and two. We’ve tried our best to shine a light on the category. With all things in the beauty galaxy, there’s always a new hope, but of course a phantom menace lurks around every corner.

Source Images: Getty Images