full-size leave-in molecular repair hair mask
4-minute leave-in treatment to reverse hair damage
A leave-in treatment mask that works on the molecular level to reverse hair damage in just 4 minutes. The K18PEPTIDE™ is clinically proven to repair damage from bleach + color, chemical services and heat* – with immediate and lasting results to restore strength, softness, smoothness and bounce to hair.
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how does the k18 mask work?
The K18 mask works as a treatment to reverse damage in 4 minutes. It’s powered by our biomimetic K18PEPTIDE™ to seamlessly fit in and reconnect broken polypeptide chains at the molecular level. As a result, disulfide bonds are also reconnected for reinforced strength along the length + width of hair—offering comprehensive, lasting, and progressive repair.
what is the k18peptide™?
K18PEPTIDE™ is a biotech-developed peptide that mimics hair’s structure to reverse damage by reconnecting polypeptide chains and disulfide bonds broken during damage from bleach + color, chemical services, and heat*
*Disclaimers
why skip conditioner?
Conditioner leaves a film that blocks our peptide from penetrating effectively. Once the 4-minute wait time is up, feel free to use a conditioner, a leave-in, or any type of product.
i noticed there’s alcohol in the formula, isn’t that bad for you?
We like to keep our formulas minimal, only using the exact amount of ingredients needed to get the peptide where it needs to go. Here the alcohol serves as an agent to optimize the hair environment for the K18 mask to work on a deeper level. Our unique blend of 3 alcohols functions to open the hair cuticle so the K18PEPTIDE™ can penetrate the innermost layer of hair, reaching the broken polypeptide chains (keratin chains).
when should i expect to see results?
Most see results after 2-3 uses. The more damaged the hair, the more dramatic the results so it may vary depending on your hair type and level of damage.
Repair damage for hair like new* in 4 minutes.
1. Shampoo, do not condition. Towel-dry thoroughly.
2. Apply 1-3 pumps based on your length and density, starting at the ends and working up towards the roots.
3. Let sit for 4 minutes. Do not rinse out.
4. Comb, add styling product + style as usual. Use for 4-6 washes, then as needed.
*k18hair.com/disclaimers
See how K18 unlocks our community's expression
- Effectiveness
- Texture
- Repair
- Frizz
- Value
- Natalie H.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50mLI recommend this productRated 5 out of 5 stars2 days agoExpensive but worth it
If you dye your hair, this hair mask is an absolute must.
Is the only product that restores what feels like natural hair? And unlike other hair masks that I have used on dyed hair, this prevents my hair from going horribly frizzy in the rain or wet weather. I buy the 50 mL bottle which is £70 and I bought my last one a whole year ago so it does last lot. I have social link there so I use one pump each time. I contacted K 18 to ask how many pumps were in a bottle and in each millilitre there is one pump so 50 pumps for 50 mls.
The way to use it is once you’ve washed your hair with shampoo and no conditioner and you wrapped it in a towel when it is damp, I pump one pump onto my hand and I spread it out over my palms and fingers and I use both hand to massage it through the ends of my hair where it’s coloured avoiding the root and paying more attention to the front and the end of the hair. Then I blow dry my hair using a ceramic brown brush and a very hot hairdryer and I always get a really lovely shiny result which I would not be able to achieve without this hair mask.
Just a note about authenticity I between purchases I bought one on vintage thinking it was someone selling an unused unopened bottle but when it arrived it was clearly fake. I could tell that it was not genuine by The comparing the two bottles of the one from Vinted and the previous one I had from K 18. Do not be tempted to buy this product anywhere other than from the supplier. If it’s cheaper, it’s…
KUK18Hair UK21 hours agoThank you so much for your incredible review, Natalie! We're absolutely thrilled to hear that the Full-Size Leave-In Molecular Repair Hair Mask has become such an essential part of your hair care routine. It's amazing that you've experienced that natural hair feeling restoration and that it's helping prevent frizz in wet weather - that's exactly what we love to hear from our community!
We're so happy the 50mL bottle has lasted you a whole year with one pump per use, and thank you for sharing those helpful application tips with other customers. Your detailed routine really shows how effective K18 can be when used properly, and we love that you're achieving those gorgeous, shiny results every time.
We also really appreciate you highlighting the importance of purchasing from authentic suppliers. It's so important that our customers get the genuine K18 experience and results they deserve.
Thank you for trusting K18 with your coloured hair and for taking the time to share such a thorough and helpful review. Your support means the world to us! ✨
- Lavanya V.Verified BuyerReviewingLeave-In Molecular Repair Hair Mask SampleI do not recommend this productRated 1 out of 5 stars6 days agoMolecular Repair Mask - Broken
Very bad packaging - arrived completely broken and product leaking. I could not even try & had to throw it away as the bottle was totally broken.
This is unacceptable for a product highly priced. I would actually give zero star.
I need a refund!!
KUK18Hair UK21 hours agoHi Lavanya, we're so sorry to hear that your Leave-In Molecular Repair Hair Mask Sample arrived completely broken with the product leaking everywhere. We completely understand your frustration - receiving a broken product that you have to throw away without even being able to try it is incredibly disappointing. This definitely isn't the experience we want our customers to have with K18.
Please reach out to our team at customercare@k18hair.co.uk with your order details so we can process a refund for you and look into what went wrong with the packaging during shipping.
- Jana G.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 35 - 44Hair Concern Frizz, Dryness, Color-care, Split-EndsHair Type Medium Density, Curly/CoilyMy Results Defined Curl/Wave Pattern, Smoother Hair, Soft Touchable Hair, Visible Difference, Bouncy HairRated 5 out of 5 stars1 week agoUnbeatable
I have not been able to find a product that does anything remotely close to this. Repairs damage and just brings my curls back to life. Pics are before, after one use, then after 2 uses and it just keeps getting better. Plus I touch my hair all day and it’s lightweight and not sticky.
KUK18Hair UK6 days agoThank you so much for your amazing review, Jana! We're absolutely thrilled to hear that the Jumbo Leave-In Molecular Repair Hair Mask has brought your curls back to life and that you're seeing such incredible progress with each use. It means the world to us to know that you haven't found anything else that compares to our formula for repairing damage. We love that it's lightweight and not sticky while still giving you those touchable, beautiful results. Thank you for taking the time to share your experience—we're so grateful to have you as part of the K18 community!
- Katrina C.Verified BuyerReviewingMini Leave-In Molecular Repair Hair Mask 15 mLI recommend this productRated 5 out of 5 stars1 week agoExcellent product
My hair due to bleaching, menopause and sun was so very dry and brittle. It felt like straw. So far I have only used K18 repair mask 3 times and I can already see the difference and my hair looks more shiny.
KUK18Hair UK1 week agoThank you for your wonderful review, Katrina! We're so thrilled to hear that the Mini Leave-In Molecular Repair Hair Mask is already making such a noticeable difference after just 3 uses. It sounds like your hair has been through a lot with bleaching, menopause, and sun exposure, so we're especially happy that K18 is helping restore that shine and improving the overall feel of your hair. Going from straw-like texture to healthier, shinier hair is exactly the kind of transformation we love to see! Thank you for choosing K18 and for taking the time to share your experience with us. ✨
- Renee H.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 45 - 54Hair Concern Chemical damage, Frizz, Fragile/brittle hair, Dryness, Split-EndsHair Type Fine/ThinMy Results Less Frizz, Visible Difference, Smoother Hair, Shinier HairRated 5 out of 5 stars1 week agoAwesome product
This product is a saving grace! After having a hair dresser have a tantrum and poured acid all over my hair and scalp K 18 has definitely helped! Great company and will continue to buy the products!
KUK18Hair UK1 week agoThank you so much, Renee! 💛 We're so sorry about your experience, but thrilled K18 has been able to help restore your hair. Your trust means everything to us! ✨