Reddit Says This $5 Mouthwash Hack Kills Maskne—But Does It Actually Work?

We asked the experts.

Woman with curly hair and mask

Getty Images

On its best days, Reddit feels like an especially fun afternoon in the high school cafeteria. On its worst days, it feels like it should be literally illegal. But amidst all the chaos, there is one bright spot on the site: r/SkincareAddiction. With more than 1.3 million members (there are 3,000 online as I type this!) it's a great place to get feedback on your routine, compare and contrast with others, and discover new products and tricks. But, of course, like every online forum, it can also be full of misinformation that runs the gamut from "oopsie daisy!" to "burned off my top layer of skin mixing acids." Pretty much anything you stumble upon should be cross-referenced elsewhere and taken with the proverbial grain of salt. So when we saw a "mouthwash maskne" hack trending across the platform, we were intrigued but decidedly skeptical.

According to one Reddit user, you can significantly reduce face mask-induced acne by rinsing your mouth with mouthwash before masking up. The thinking goes that your mouth is a jungle of bacteria and when a mask is in place, covering your mouth, some of that bacteria seeps out and can form zits. By swishing with some antiseptic mouthwash first, you kill all of that bacteria and never give it a chance to spread to your face. As a bonus, the post suggests slathering on an occlusive like Vaseline before slipping a mask on can also create a barrier between your skin and any rouge bacteria.

Screenshot of reddit post


Sounds too good to be true, right? The $5 bottle of Listerine you probably already have in your bathroom cabinet as the cure to your maskne woes? That's what we thought, too—until we asked Dr. Rachel Nazarian, dermatologist and member of Byrdie's Beauty & Wellness Review Board. While the Vaseline part is sketchy (more on that in a minute), the mouthwash hack is actually totally legit and backed by science.

"I actually recommend using a mouthwash to decrease bacterial colonization of the oral mucosa as well!" Dr. Nazarian tells me over email. "I've found that by decreasing the bacteria in the mouth, you're not rebreathing as much bacteria onto the skin, and that can help preserve the natural flora and pH of the skin much more effectively." Dr. N goes on to explain that the additional bacteria and unbalanced pH can cause those maskne flair-ups alongside rosacea and even good, old-fashioned regular acne. There is one caveat, though: you'll have to rise pretty regularly to see a real difference.

"Keep in mind that our mouths will recolonize and regrow our natural bacteria quickly, so the mouthwash should be used every morning, or whenever you wear your mask, for continued improvement," Dr. Nazarian says.

Aluminum bottle of mouthwash
Colgate Swish Antibacterial Alcohol Free Mouthwash $4.99

As for the Vaseline, that's a completely different story. Despite claims, an occlusive under your mask doesn't keep bacteria out—it traps it inside. Dr. Nazarain says a thick, barrier-type product can actually trap heat against your skin and make maskne even worse. Unfortunately, that's not even the worst of it. Not only can it aggravate acne, but it can reduce the efficacy of your entire mask.

"It can interfere with the barrier the mask needs on the skin to keep it effective and keep us safe," Dr. N warns. "Anything that stands between our mask and our skin decreases the effectiveness of our mask and compromises our security against Covid." And I don't know about you guys, but I'd rather risk some maskne than take a chance on spreading (or contracting) a virus.

To try out the mouthwash acne hack for yourself, make sure you're picking up an antiseptic mouthwash—you'll usually see that word on the label along with a line about fighting germs. Those are the ones you want to grab. No need to shell out on anything expensive, either. Drugstore anything will work just fine but if you don't like how it looks on your counter, allow me to put you on: this $26 set of two glass mouthwash decanter from Amazon hold the liquid in beautiful containers worthy of a thousand IG Stories and will last a lifetime with proper care.

Two glass mouthwash bottles
Upper Midland 2 Mouthwash Bottles Glass Dispenser Containers with Mouth Wash Labels, 24 oz $25.99

One last thought when it comes to Reddit: Hacks and information spread on the discussion platform are sometimes one part completely legitimate, cosigned by medical professionals; the other, misinformed and potentially dangerous. Scroll the forums freely, but always keep that in the back of your mind. If you ever come across something that looks a little sus, investigate it yourself. Or come to us, Byrdies!

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