I Tried The Hair Mask People Say Is Better Than Olaplex & I Have Thoughts

If you put a bunch of beauty editors in a room, it won't be very long before the conversation turns to the products we're lusting over. Lately it's The Ordinary's segue into haircare with a brand-new shampoo and conditioner, not to mention SkinCeuticals' new serum for pigmentation and the Nip + Fab face pads that are said to transform congested skin. But one product in particular has really whipped up interest across the board — so much so that most of my conversations this week with beauty-obsessed colleagues have revolved around it.

Enter: K18 Leave-In Molecular Repair Hair Mask.

If you haven't heard of K18 until now, that's because it launched in the UK at Cult Beauty just last month. It's already huge among hairstylists and colourists across the pond, though. In the US, Refinery29's beauty director Sara Tan is a big fan and I've heard it compared to Olaplex (one beauty editor even said it's better). TikTokers are sold, too, with the hashtag #K18 gaining an impressive 10.8 billion views. So what's in this seemingly magic hair potion? And is it really that special?

Similar to Olaplex (whose star ingredient is bis-aminopropyl diglycol dimaleate), K18's hair mask harnesses the transformative power of a patented ingredient: a peptide, which is basically a protein. Peptides are made out of amino acids and it's these which the product shuttles directly into your hair strands to stitch broken bonds back together. Lots of things can break hair bonds, such as bleach and heat styling, which can make hair feel dry and tangled. Just like Olaplex (my favourite is No.8 Bond Intense Moisture Mask for taking parched hair and making it glossy), K18 has gained devotees everywhere for supposedly breathing life back into hair that's a little worse for wear.

Mine really is worse for wear. Last year I had it bleached and dyed blue. When my roots began to grow out, I decided that I'd get the blue stripped out and my hair dyed back to brown. It's naive of me but reversing the colour didn't undo the damage — far from it. Put simply, my hair is in dire need of some TLC. I've got a roster of great shampoos, conditioners and styling products but every now and again my lengths scream out for a surge of moisture in the form of a mask or leave-in treatment. I know I'm not alone. Lots of us have switched up our hair colour, or are at least thinking about it, with shades like peachy copper, Scandi blonde and expensive brunette taking hold of hair salons everywhere. With K18 touted as the ultimate companion for dyed hair — actually, all hair — I had to give it a go.

The product comes in three sizes and in my opinion is on the spendy side — 5ml for £9, 15ml for £25, 50ml for £55 — though I am reassured that a tiny bit goes a very long way. Unusually, you aren't required to wash this mask out. Simply shampoo and rinse like normal but skip the conditioner. Once you're done, give your hair a squeeze to get rid of any excess water (you can towel-dry it if you like) and pull a small dollop through your hair from root to tip. After four minutes you can follow up with your styling products and dry and style your hair like you usually would.

As my hair is so brittle I was wary of shelving my conditioner so I reached for my most moisturising shampoo: Amika The Kure Bond Repair Shampoo, £16. I rinsed and towel-dried my hair like normal (I always use an Aquis microfibre towel, which I believe is gentler on fragile strands) and pulled a pump and a half of the K18 mask through my thick hair from root to tip. After just over four minutes I followed with a hair product I love right now — ARKIVE The Good Habit Hybrid Oil, £14 — and rough-dried on medium heat.

I'll bring you the positives first. My hair felt instantly thicker and a lot stronger. The volume was long-lasting, even after styling. I could tell that my strands were so much more resilient during straightening and I wasn't terrified that my hair would totally snap off thanks to the bleach. There aren't any negatives per se but I really expected this to work miracles and it fell short in terms of feel. I expect a lot from my hair products and one of my main requirements is silky, glossy hair. While this did exactly what it says on the tin and fortified my fragile strands well, my hair wasn't particularly soft or frizz-free, which was disappointing.

So how does it fare compared to other speedy hair conditioners, like Elvive Dream Lengths Wonder Water, £9.99, and salon-favourite Kérastase Chroma Absolu Soin Acide Chroma Gloss, £37.60? When it comes to texture and finish, I have to admit that I prefer both of these — particularly Wonder Water, which is a snip of the price of K18. Chroma especially helps to patch over broken and split strands temporarily. If you're an R29 regular, you'll know that I'm a huge Olaplex No.8 stan, too. Unlike K18 you're required to rinse it out, but it delivers both softness and strength.

I'd probably reach for K18 when my hair is in need of a cut and my split ends are at their worst. It's pretty much the hair equivalent of scaffolding and props up limp, fragile strands brilliantly. But with hair movements like French glossing and liquid hair trending, the products I mentioned above are the ones I'll be keeping in rotation this year.