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K18 vs Olaplex hair masks: Which treatment for damaged hair is really the best?
Following that controversy, we find out if it’s the cult classic or new contender that reigns supreme
Sabine Wiesel
Wednesday 06 April 2022 17:03 BST
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Bleach, colour, chemical treatments, excessive heat styling: these are just some of the things we do to our hair that can cause damage to our strands which can show up in the form of anything from frizz to breakage.
While standard hair masks work on the outside layers of the hair cuticle boosting moisture levels, hair treatments that work on a molecular level travel deeper into the hair strand, working on the inner layers repairing damage from the inside out.
The first brand to offer this state-of-the-art technology in an at-home formula was Olaplex’s original bond-building haircare line. It’s loved by hairdressers, beauty editors, influencers and consumers alike, for its hair-strengthening ability. And if there’s a favourite to be had, it’s often the no 3 hair perfector (£26, Lookfantastic.com) – Olaplex’s bestseller and now a cult classic.
Despite being such a well-loved treatment it’s also recently become the subject of much concern and debate on social media. It was brought to attention that it contained lilial – a fragrance often used in cosmetics that’s been linked to infertility issues and which was banned in the EU from 1 March.
This ingredient has now been taken out globally and used to contain such a tiny amount that experts say it’s nothing to worry about. However, the controversy sparked a debate in the beauty world on whether the new K18 leave-in molecular repair hair mask (£9, Cultbeauty.co.uk) – which launched in the UK in the middle of the frenzy – was a better option.
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The question is, is it just hype, a well-timed launch or does the new hair treatment live up to the love it’s been receiving across the pond? To find out, we put the two head to head.
How we tested
Our tester has dry, highlighted hair that’s prone to breakage with regular fall out in the shower – the perfect candidate to test the new hair-repairing treatment. Already a fan of the Olaplex no3 perfector, both were tested and marked on two-weeks use of each, with both being used as directed without any styling products to test each treatment’s true solo performance. Here’s which formula came out on top.
Olaplex no 3 hair perfector, 100ml
Buy now£26, Lookfantastic.com
The best-selling hair treatment in the Olaplex line-up, this product uses the brand’s bond-building patented and ground-breaking hair tech. So we don’t lose you in the science of it, in the most simplified form it works by infusing strands and repairing broken bonds that go to make up the hair structure.
These bonds are often damaged from salon trips and daily aggressors, manifesting in frizz, dryness, breakage and so on. By doing so, it promises to repair damage, strengthen strands and reduce breakage in all hair types.
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It’s a pre-shampoo treatment, so you apply it to damp hair before shampooing – leaving a generous amount of the creamy product combed through for 10-minutes. This makes it much more convenient to use than standard masks and treatments, as you can apply and go about your daily routine without any shower time-wasting while it gets to work.
Our tester has long been a fan of this product but hasn’t used it in a while. After re-introducing it back into her routine, she had forgotten how much stronger her hair feels when using it at least once a week. Dry, brittle strands started to feel softer and look healthier the more we used it, and the same goes for less breakage and shower fallout.
K18 leave-in molecular repair hair mask. 50ml
Buy now £55, Cultbeauty.co.uk
Similar to Olaplex (£26, Lookfantastic.com), this treatment has a patented ingredient – but in this formula, the lead is the K18Peptide. Our hair strands are made up of keratin chains that become weak and break when hair gets damaged, and the brand says this peptide travels to the inner layers of hair reconnecting these broken chains – promising to bring damaged hair back to its original, youthful state.
Where this product differs to the Olaplex formula is in use. You apply it to freshly shampooed strands, skipping the conditioner. After, towel dry the hair and apply the concentrated cream. We thought this could end in tears as a detangling product is usually a must for our tester, but the treatment feels conditioning so with the help of a wide-tooth comb we quickly got through any knots.
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A little of the product goes a very long way, and you can use anywhere from one to four pumps. Our medium-length, medium-textured hair only needed two to cover the whole head once combed through. It’s a leave-in formula compared to Olaplex, which is a washout. Leave on for four minutes and then style as normal, without rinsing. Easy!
We trialled as the brand recommends, using it for up to six consecutive washes and then every three-four after that. After one use, there was a marked improvement in how much stronger and healthier hair felt and looked. However, with ongoing use expect the best results to come a few applications later (it did for us) with hair feeling extra silky soft and looking glossy after four-five applications.
The verdict: K18 leave-in molecular repair hair mask vs The Olaplex no 3 hair perfector
The Olaplex no 3 hair perfector is a modern-day cult classic hair care product that was always going to be hard to live up to, let alone beat. And while it’s on par performance-wise, the K18 leave-in molecular repair is a much easier to use product in our eyes.
We can’t recommend both treatments enough if you have coloured, dry or damaged hair. Both transform damaged strands to a more manageable mane the more you use them with stronger, softer and healthier results seen after just one use.
For us, K18’s treatment takes less time to use and is easier to fit into our haircare routine. The fact that it takes just four minutes to work in hair and there’s no rinsing out, makes it as fuss-free as just applying a styling cream – just one that transforms the way hair looks and feels.
There is no denying the downside to the K18 (50ml) is its price tag. While it may appear around double in price compared to Olaplex, you actually use so little that they work out the same in price when you compare amounts used per application. The brilliant thing is, you can see how it works for your strands without the big investment, as it also comes in a small but mighty 5ml and a 15ml mini.
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