I credit the Dr. Dennis Gross LED mask for my best skin to date

I used the Dr. Dennis Gross DRx SpectraLite FaceWare Pro as directed by Dr. Dennis Gross himself. That is: once daily (after cleansing, but before carrying out the rest of my skincare routine each evening). Each session only lasts three minutes, which made the commitment to testing a whole lot easier. I've been testing the Dr. Dennis Gross LED face mask constistently for the past year, over the course of twelve full skin cycles. I've also ensured other members of the Glamour team have tested this product, noting their before and after photos, and commentary on results.

To ensure a fair verdict, I made sure to keep my wider skincare routine more or less the same (I used my trusty SkinCeuticals C E Ferulic vitamin C serum, a hydrating B-Hydra serum from Medik8, a Korean sunscreen from Skin 1004, the Tatcha Dewy Skin Cream and, for nighttime, my Medik8 Crystal Retinal). I assessed precision (clinically-proven wavelengths of light are key; the most clinically-proven wavelengths of light, 633 nanometers & 830 nanometers), coverage and fit (any gaps between the mask and face can reduce effectiveness).

• My skin type: Dry & sensitive skin.
• Main skin concerns: Mild rosacea & PCOS-related breakouts.
• Testing period: 1 year.

I've been a beauty journalist for the past five years, which means I've tested my fair share of red light therapy masks – as well as other launches, from Korean serums to red light therapy helmets, LED eye masks and moisturisers. You could say I know more about the best new beauty products that you average beauty fan.

During my career, I've seen lots of trends come and go – but the consistent and exponential rise of red light therapy has been the most interesting to me. So, when it comes to red light therapy specifically, I have interviewed experts – including Dr. Dennis Gross himself – attended product launch events, attended panel talks and done a hell of a lot of reading around the topic. As such, I had a lot of expertise when it came to assessing quality of this product, and determining whether the technology behind the mask genuinely justifies the price.

The FDA-cleared Dr. Dennis Gross LED mask features two types of LED therapy – red and blue (100 red-mode LEDs and 62 blue ones). You can use them separately or together for a total of three treatments, depending on which benefits you want to focus on. According to Dr. Dennis, “red LED works to stimulate collagen production, reducing the appearance of fine lines, wrinkles all while reducing inflammation.” Elsewhere, he also shares that “blue light targets and kills acne-causing bacteria, treating and preventing breakouts.”

“Just like a topical active ingredient, our skin cells have receptors for red LED,” he explains. “When the light connects with these receptors, it effectively tells our skin to start creating more collagen – the key to healthy, youthful-looking skin.”

“Red LED also stimulates blood flow. Acne-causing bacteria also have receptors – one is for blue light. When a specific wavelength of blue light connects to this receptor, it self-implodes. This is how the blue light can uniquely target the bad bacteria without disrupting your skin's moisture barrier,” says Dr. Dennis.

Denise Primbet wearing the mask.

The mask itself features a hard shell and a cushy layer of silicone on the inside, as well as adjustable straps. All you need to do is push the button at the top to turn it on switch between LED light settings. According to Dr. Dennis, what sets this mask apart from other options is the fact that you only need to use it “3 minutes per day while others can be upwards of 20 minutes. This is because of the mask’s power – you are able to get the same energy in less time.”

It's also completely wireless and can be used hands-free, as opposed to other tethered LED masks that make it harder to multi-task and walk around during use. Dr. Dennis also shares that the design itself ensures that it “follows the face's natural contours allow for maximum light penetration.”

Elsewhere, there are "clinically proven wavelengths that provide optimal results. For example, blue light has been shown to be most effective at 435nm. When it comes to red light, using a device that incorporates a spectrum of red light including amber, red, deep red and infrared will deliver the best results,” he shares.

The Dr. Dennis Gross LED mask is designed to safely include in your skincare routine with one three-minute treatment. You can't use it for more than three minutes at a time, as the brand says that skin cells become fully saturated after one three-minute session, and can’t absorb any additional LED energy.

However, you can use the device more than once a day to help bring down redness, inflammation or puffiness, and you should see results within 10 weeks.

Yes. The Dr. Dennis Gross LED mask is the type of daily product that works as an acne treatment and prevention in one, provided you're patient and consistent.

"It will work better for inflammatory blemishes but it can help heal and restore all acne-prone skin," says Weiser. "Acne should show early signs of improvement in two to four weeks of light therapy, but it will take two to three months of consistent treatment for optimal results." (The brand also states upfront that a proper course of treatment should last at least 10 weeks, although you'll start seeing the benefits well before that).

TBH, there are few that I found. I noted above that the face mask felt heavier than expected – something which I didn't find with lightweight models like the CurrentBody Series 2 mask. Further, given how chunky it is, I'd like to do more investigation into whether the mask sits the correct distance away from the face to serve the best results.

The second con – there are two things it can't cure. Congested pores (for blackheads, try these K-beauty sheet masks instead) and everyone's least favourite form of breakout, cystic acne.

Zeichner concedes that the technology might help reduce the size of some acne cysts, but it can't go further than that. "Cystic acne is triggered by hormones, so light therapy alone is often not sufficient because it is not treating the underlying hormonal trigger," says Weiser. Those exceptions aside, you do get to enjoy plenty of upsides in one sleek package. I particularly like that it does its thing in a scant three minutes, without my having to lift a finger (after powering it on, that is).

Otherwise, the main con to note is the price – but you can rest assured that it does deliver on its claims. Splurge in peace with Zeichner's final verdict in mind: "If the device does not cause too much harm to your wallet, I give it the green light." I'll stop short of claiming that this is a necessity for everyone, but I'm officially sold. My justification: It's a derm visit, spa day, and photo op in one.

It's a resounding yes from me. I'm rarely someone who endorses premium products, however, this is one of the rare cases when the technology behind it and the benefits fully justify the price. Although in-clinic LED treatments may be more effective, I'd still argue that you're less likely to pay a visit to your dermatologist every week, and considering that you can use this mask every day, you can maximise the benefits a lot faster. So, unless you're dealing with a more urgent skin concern like cystic acne, this LED face mask is your best bet at maintaining healthy skin. In fact, I'd go as far as to declare that it's easily one of the most effective skincare devices I've ever tried.