This Painless Light Treatment Is Research-Proven To Fade Acne And Dark Spots Without Irritating Skin (2025)

The skincare industry’s current mantra du jour? “Let there be light.”

Need proof? Just take a scroll through social or a stroll through your local Sephora to see countless light-based devices promising better skin. The majority tout red light as the primary player—but that’s not the only hue worth considering. Blue light is also emerging on the at-home scene, offering its own set of unique benefits. “Red light is definitely getting hyped right now, but blue light is also worth considering, especially if you’re dealing with acne,” says Brooke Jeffy, MD, a board-certified dermatologist in Scottsdale, Arizona.

Meet the experts: Emily Wood, MD is a board-certified dermatologist at Westlake Dermatology’s Marble Falls and Austin, Texas locations. Brooke Jeffy, MD is a board-certified dermatologist in Scottsdale, Arizona. Ashish Bhatia, MD, is a board-certified dermatologist in Illinois.

Aside from that, how does it differ from its more popular counterpart and who should consider using blue light? (Also, is this blue light different than what’s coming from our phone screens…that we’ve been told is bad for our skin?)

Ahead, answers to all of your burning blue light Qs.

What is blue light?

“Blue light is a specific range of wavelengths, 380 to 500nm, within the visible light spectrum,” explains Emily Wood, MD, a board-certified dermatologist at Westlake Dermatology’s Marble Falls and Austin, Texas locations. FYI, we’re exposed to blue light constantly. It’s in sunlight and emitted from the screens of electronic devices, notes Ashish Bhatia, MD, a board-certified dermatologist in Illinois. As far as skincare goes, blue light is hardly the new kid on the block. It’s long been used by dermatologists to treat both acne and pre-cancerous skin lesions, Dr. Bhatia notes.

How is blue light different from red light?

At the simplest level, different colors of light have different wavelengths. Blue light has shorter wavelengths (around 400-500nm, as mentioned) compared to red light, which ranges from 620 to 750 nm. (Green light, which is also sometimes used for skin, falls somewhere in between the two, at 500-570 nm.) Blue light acts more on the surface of the skin while red light penetrates deeper, explains Dr. Jeffy.

They also have very different effects. Red light is typically studied and used for its anti-aging benefits and how it impacts collagen production; blue light is most often correlated with treating acne, Dr. Jeffy points out. (Keep reading for more on those specifics.) In related news, that’s likely part of the reason why there are way more red light than blue light devices out there. “To put it plainly, more people are after the youth-boosting benefits promised by red light,” she says. Dr. Bhatia agrees, calling blue light more niche. Still, it’s certainly no dud and—spoiler alert—is especially worth considering if you’re battling blemishes. To that point…

How does blue light benefit skin?

Blue light is most commonly known as an effective treatment for acne-prone skin, but it has other powers, say our docs. Here's are all the ways it can give your complexion a boost:

• Blue light battles acne. The most well-studied, proven benefit is undoubtedly its effect on breakouts, specifically its ability to kill acne-causing bacteria. How exactly does it do that? Here's the quick explanation: All bacteria, but especially acne-causing C.acnes, produce porphyrins, a byproduct of the bacteria’s metabolic processes, notes Dr. Jeffy. These porphyrins are light sensitive—to blue light in particular. Exposure triggers a chemical reaction that ends up killing the bacteria, she explains. (FYI, this effect on porphyrins is also why blue light can be used as part of what’s known as photodynamic therapy, an in-office treatment for precancerous skin lesions. However, this involves the use of other medications and can only be performed by a doctor.)
• Blue light quells inflammation. While the majority of the data on blue light revolves around these antibacterial effects, some research shows that it’s also anti-inflammatory, potentially helping to treat inflammatory skin conditions such as psoriasis and eczema. In the case of the latter, it also decreases the unwanted increase of keratinocytes (skin cells), offering further benefits, she adds. How exactly does blue light help? “Most of the proposed mechanisms of actions relate to the ability of blue light to down-regulate inflammatory molecules known as cytokines,” explains Dr. Wood.
• Blue light softens acne scars. And going back to acne, blue light may also help minimize acne scars, notes Dr. Bhaita. One 2020 study showed that it down-regulated the cells responsible for irregular collagen contraction that leads to abnormal, hypertrophic (AKA raised) scarring.

Still, at the end of the day, all of the derms we spoke with agree that it’s best to think of blue light primarily as an acne-fighter.

But isn't blue light bad for your skin?

Let’s address the elephant in the room. Are we talking about the same kind of blue light experts warn against, the kind that disrupts our sleep and damages our eyes…and skin? Yep, it is. So what gives? “Blue light is dose dependent,” notes Dr. Bhatia. In smaller, targeted amounts (i.e. what you get from an in-office treatment or at-home tool) it can do good things for your skin. But with chronic, prolonged exposure (think staring at your beloved screens 24/7), it can damage the skin, specifically causing inflammation and pigmentation, he explains. Dr. Wood agrees: “Much of the harm caused by electronic devices is due to the length of exposure,” she says.

All that’s to say, targeted, blue light therapy will do good things for your skin, especially if you’re dealing with acne. (However, if you’re really worried about sleep disruptions, Dr. Wood says it’s not a bad idea to avoid using blue light masks in the evening.) It’s also a good move to wear a physical sunscreen daily to minimize the damaging effects of blue light from sun and screens, Dr. Bhatia advises. (Chemical sunscreens don’t block blue light.)

The difference between in-office blue light and at-home devices

As is the case for pretty much all energy-based devices, anything you can use at-home is less intense (and theoretically effective) than the in-office counterpart. Blue light home devices are going to have fewer bulbs that are less powerful than the ones on the devices you'd find in medical offices, Dr. Wood points out. “That sometimes means results from an in-office device may not be achievable with an at-home mask,” she adds.

Still, the at-home versions are undoubtedly more convenient and easy to incorporate into your regular routine.

How to use blue light at home

As mentioned, consider blue light if you’re dealing with acne—but it shouldn’t be a standalone treatment. “Think of it as an additional tool in your armamentarium,” says Dr. Bhatia. The nice thing? Unlike adding, say, another topical ingredient to the mix, blue light is very well-tolerated so you don’t have to worry about irritation, he adds.

There are a few key things to consider when shopping for an at-home blue light mask or device. Dr. Jeffy says you’ll want to make sure that the tool is actually emitting the specific wavelengths in the blue light range: “If it doesn’t list the actual wavelengths, that’s definitely a hard pass,” she says, noting that most at-home blue light devices fall within the 400-495nm range. Another red flag? At-home LED masks are considered Class II devices, meaning they can be FDA-cleared, but not FDA-approved; if you see something touted as the latter, it’s likely a marketing scam, she cautions.

Worth noting: You’ll be hard pressed to find a tool that offers straight-up blue light; most feature it as an option along with red light, or combine them. Happily, Dr. Jeffy says the two work nicely together and have synergistic benefits, particularly if you’re considered about both breakouts and wrinkles. When it comes to frequency of use, your best bet is to always follow product directions. However, Dr. Bhatia notes that once or twice per week is often sufficient for acne purposes in particular.

Ultimately, blue light doesn’t have the same type of universal benefits that some other wavelengths—ahem, red light—do. That being said, if you’re feeling blue about breakouts (see what we did there?) it’s worth considering adding a blue light device into your complexion clearing protocol. But the best news? Most of the LED tools out there offer make it easy to reap the full spectrum of light’s skincare benefits.