I’m pretty skeptical when it comes to viral products—it’s practically my job to wade through what actually works and what’s B.S., but trust me when I say K18 is very much worth the hype. Though the hair mask has recently been gaining steam on TikTok, it’s actually been making noise in the beauty community since it launched in 2020; it’s been endorsed by some of the best colorists and stylists in the biz—which is why it’s crazy that it’s taken me so long to try it.
Before we get into my results, let’s discuss why exactly this product has been so highly praised. Unlike traditional hair masks which simply hydrate and smooth the outside of your hair to makie it appear softer and shinier, the K18 Leave-In Molecular Repair Hair Mask goes in on a deeper level, repairing damage from the inside out. “K18 travels into the innermost layers of hair and can renew hair’s core strength elasticity to bring hair back to its near-original, youthful state,” says Yusef, celebrity hairstylist and K18 partner. “K18 does everything bond builders do, and goes a step further by also repairing polypeptide chain breaks on the y-axis. Hair both looks and feels like new.”
Yusef notes that great hair starts with healthy hair and recommends the treatment to anyone, particularly those looking to reverse damage from heat, chemical services, and bleach. Celebrity colorist and co-owner of New York’s Mark Ryan Salon, Mark DeBolt—who is not affiliated with the brand—is also a fan of the mask as well as K18’s salon-only mist. He says he loves the mask in particular for his clients who are trying to grow out their hair, or who lighten with highlights.
My hair isn’t in the worst shape, but the thought of repairing years of bleach damage (under a red gloss) with a leave-in product was too appealing to pass up. Plus, I haven’t had a haircut since early fall, so my usually bouncy hair is starting to look frail and scraggly, which is why a few weeks ago, I decided to give K18 a go.
As far as application goes, it takes some getting used to since it’s different from your average mask. Instead of letting it sit on wet hair for up to 10 minutes and rinsing it out, you use it as a leave-in treatment. “We tell our clients to shampoo their hair, but do not condition,” says DeBolt. “After getting out of the shower, towel-dry hair well. Apply two to three pumps onto your palms and rub together to distribute evenly over hands. Begin application of the mask first onto the most porous and most sensitized parts of hair: the midlengths and ends. Then, using what little product is remaining on your hands, apply closer to the root. Use either a wide-tooth comb or a detangling brush to brush hair out and distribute product more evenly.” Be sure to let it sit for four minutes to activate, after which you can add other styling products or style with heat as usual.
Though it feels somewhat unnatural to skip conditioner and apply a mask fresh out of the shower, after doing it a few times I can’t really imagine going back to traditional masks. There’s no killing time in the shower while it does its thing or getting out to let the mask sit and then back in to rinse. The mask quickly absorbs into your hair with minimal residue and is very lightweight—moreso than a traditional conditioner or leave-in—making it a great option for finer hair like mine.
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I’ve been using K18 for a few weeks now—every wash for four washes at first, as recommended by the brand, then about once a week—and the difference is pretty noticeable. My hair feels soft and smooth, and looks bouncier and healthier, especially when I blow it out. I’ve also noticed my slight waves are more defined, and my broken baby hairs near my crown are less likely to stick up straight since incorporating K18 into my routine. Basically, it’s shampoo-commercial hair in a bottle—it’s worth the price tag and the hype.
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Bella Cacciatore is the beauty writer at Glamour. Follow her on Instagram @bellacacciatore_.
