We’re always looking for new treatments in our battle to keep our curly hair in good condition and the K18 Biometric Hairscience Treatment seems to be catching everyone’s attention.
This innovative new treatment is said to have a variety of benefits, including the ability to REVERSE DAMAGE. Yes, reverse it.
Ok, back up a sec. What exactly is the K18 hair treatment, and will it benefit curly hair? Let’s take a closer look.
Sell K18 to me and my curly hair!
Ok, the claims are bold so this is going to be easy.
It reverses damage caused by
- Bleaching and colouring services
- Chemical services
- Heat
In other words, the patented K18 peptide is able to reach the innermost parts of the hair to repair broken keratin chains. It restores hair’s core strength and elasticity.
Curly hair will always benefit from additional treatments. As well as dryness, curly hair has ‘uneven keratinization’ which makes it more fragile. This has to do with the way cell groups are arranged in textured hair. It’s pretty technical but it means that textured hair is more fragile, and more easily damaged.
This all means that wavy/curly/textured hair is an ideal candidate for the kind of repair and strengthening offered by K18.
Why is K18 different to other conditioning masks?
Conditioning treatments and masks just conceal damage or make hair feel better without actually repairing any damage. They hydrate the outer layer of the hair only.
Why is it different to other rebonding or bond-building products?
Ok, this is the nitty gritty because we can assume this research is based on a comparison to Olaplex (although K18 are careful not to state this categorically on their website).
The traditional bond builders work in the cortex of the hair while K18 goes deeper, right into the inner structure of the hair’s core to target broken polypeptide chains. The kicker here is that K18 also repairs broken disulfide bonds. (Olaplex fans know that this is the specific type of bond targeted by Olaplex technology).

My own review of K18 for curly/wavy hair
I’ve tried the Leave-In Molecular Repair Hair Mask.
The main thing that I have to say is that my hair felt amazing afterwards. Genuinely. I could tell a difference and a difference that, if I’m really honest, I have never felt with any Olaplex product. I know that both products work on a molecular level and that you won’t necessarily experience a tangible change in your hair but…I can’t help but want my hair to feel nicer after I’ve spent this much on a hair product.
More importantly, I’m on board with the science. The K18 website is a library full of information and studies on different hair types. I’m willing and happy to accept their research.
The Leave-in Mask is easy to use, too.

How do you use it?
Just like Olaplex (sorry for always comparing), it requires an adjustment to your routine. This is not a pre-shampoo treatment, however. For this alone I’m grateful – that extra step always got me. Perhaps I’m being dramatic but wetting my hair pre-wash, and then applying product always felt a bit much.
With K18 the change is post-shampoo. Shampoo your hair as normal and then hold the conditioner. This is difficult because every fibre of my being wants to reach for the conditioner bottle at this moment.
The reason? Conditioner acts as a barrier to the K18. Without it, the peptides can reach further into the strands. Essentially conditioner gets in the way.
It goes like this
- Shampoo
- Towel dry
- Apply K18 Leave-In Molecular Repair Hair Mask
- Wait 4 minutes (this is how long magic hair repair takes)
- Style as usual (or apply leave-in conditioner then style if your hair is really dry)
Is K18 Curly Girl Method approved?
This is interesting. In a word no. It’s like K18 are one step ahead of us, though. The formula contains alcohol but they are very keen to explain why.
It turns out alcohol is crucial to K18 working. The alcohol opens up the cuticle, allowing the product to penetrate deeper into the strands.
In Conclusion
Backed by a lot of science, K18 offers up the kind of game-changing treatment that those of us with curly hair are always searching for. Big promises, yes, but my hair feels lovely as a result of the K18 Leave-In Molecular Repair Hair Mask and I’m going to keep using it. My bleached, tinted, fragile, high-porosity hair is thanking me.
All opinions in this post are my own.
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