I’m sorry to say, you’ve been using your K18 hair mask all wrong (2024)

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Mind = blown

By Clare Stephenson

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I’m sorry to say, you’ve been using your K18 hair mask all wrong (1)

It turns out that me and Hailey Bieber have something in common: we both love the K18 Leave-In Molecular Mask. As soon as it jumped onto the beauty scene, it quickly amassed a huge social media presence, gaining millions of TikTok views and a stellar celebrity following.

My journey with the K18 mask began when I, regretfully, dyed my hair blonde. Many bleaching appointments later and I was left with broken and brittle strands. But as soon as I introduced the K18 mask into my routine, I started to see hope again. In a matter of weeks, my poor strands felt and looked stronger, so I thought I cracked the K18 code.

Well, it wasn’t until I booked a professional K18 hair appointment, that I realised I was using the mask all wrong. And I’m afraid to say, you probably are too.

How to use the K18 Leave-In Mask

If you’re a fan of K18, you’ll know that the treatment should be used as a leave-in mask. After shampooing, towel dry your hair without using conditioner (I know, it feels weird but conditioning will prevent the formula from properly penetrating your strands) and then apply a few pumps of the mask. The brand also advises waiting four minutes before styling. But here’s the crucial piece of information that I never knew.

K18 Leave-in Molecular Repair Hair Mask

I’m sorry to say, you’ve been using your K18 hair mask all wrong (2)

Before applying, the cream should be rubbed in between your hands until it transforms into a white paste. Now before you let your thoughts run away with you, doing this doesn’t make the product work any harder. It just means that you can be more precise in knowing where you put the product.

So, why is this important? One, it means that none goes to waste. And, two, the K18 mask is a great example of ‘you can have too much of a good thing’. Luckily, the science behind the formula means protein overload isn’t an issue – this is where you can pump your strands with too much keratin, causing them to become brittle. But where people tend to slip up is by applying too much product, which can lead to build-up.

Other hair products (we’re talking serums, dry shampoos, conditioners) can create a layer of residue overtop your strands, preventing reparative treatments, like K18, from effectively penetrating. This will also contribute to that dry and brittle feeling.

So, your best bet? Make sure to wash your hair with a hard-working clarifying shampoo (see my edit of the best ones here) and then follow with a small layer of the treatment mask – used the correct way, of course – to ensure the ingredients are reaching the deeper layers of the cuticle. You only need to use it every four to six washes to see results which, seeing as the full-size bottle costs £70, I’m more than happy to comply.

If you’re wondering how the magic happens, let's dive into what the K18 mask is – and what it’s not. On countless occasions, I’ve heard friends alike K18 to Olaplex. But, actually, it’s quite different. While they’re both guided by the same principles of reversing damage, what sets K18 apart is that it goes deeper into the hair cuticle to heal from the inside-out.

What's the difference between K18 and Olaplex?

Olaplex uses the patented bis-aminopropyl diglycol dimaleate to rebuild broken disulfide bonds – the bonds responsible for your hair type. However, the K18 mask reconnects and repairs broken keratin chains, thus promoting stronger and more elastic hair. Think of your hair structure like a woven basket: the K18 mask pulls together this network making it harder to pull apart, so it’s especially useful for seriously bleached or heat-damaged lengths.

Don’t get me wrong, I’m a long-time Olaplex fan too, but what I also love about K18 is that it’s a time saver. You can skip conditioner (another win for my bank balance) and you don’t need to rinse the product out.

As for my hair, I mean, I think the results can be explained via the science. Of course, I rely on other favourites to boost shine or reduce frizz (K18 won’t excel in this department) but for when my ends are looking particularly scraggly, or if I’ve picked up the curlers a bit too often, nothing else compares. As for my revelation, yes it takes a smidge more effort to work the product in, but if you’re cashing out on the product, you don’t want any to go to waste.

I’m sorry to say, you’ve been using your K18 hair mask all wrong (4)

Clare Stephenson

Beauty Ecommerce Writer

Clare Stephenson is a Beauty Ecommerce Writer for Cosmopolitan, Women’s Health, Red and Good Housekeeping, covering all things makeup, skincare and hair care, as well as deals events including Black Friday and Amazon Prime Day.

Clare has been an ecommerce writer since 2022, writing matter-of-fact such as deep dives into skin concerns and filled with her favourite products for every budget and need.

Before working at Hearst UK, she received a BA degree in Multimedia Journalism at Bournemouth University, focusing her studies on the world of magazines and editorial. From there, she worked as an editorial assistant at Voir Fashion Magazine, covering events like Fashion Week and interviewing reputable brand founders, including Rea Ann Silva creator of Beautyblender.

When she’s not testing the latest and greatest products, you can find Clare sifting through vintage clothing stores in the city or horseback riding in the countryside.

Follow Clare on Instagram .

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I’m sorry to say, you’ve been using your K18 hair mask all wrong (2024)
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