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
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- Jill D.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50mLI recommend this productAge 55 - 64Hair Concern Heat damage, Chemical damage, Frizz, Fragile/brittle hairHair Type Thick/Coarse, Straight/WavyMy Results Visible Difference, Soft Touchable Hair, Less Breakage, Less Frizz, Stronger HairRated 5 out of 5 stars2 days agoLove this product!
I have long, thick, bleached blonde hair. My best friend is a hair stylist, so I always use professional products and have always had beautiful blonde hair! However, I made the mistake of straightening it without a heat protector or leave in, because I was in a hurry one day and I literally fried my hair, because the straightener was on 450*! So I was told by my best friend to use the K18 hair repair mask, but I was hesitant because of the price of the small full size bottle. However ,I trust my hair stylist, so I purchased it. The first time using it I could feel and see a huge difference and I couldn’t believe it? I did have to use 4 pumps because of the length and thickness of my hair, but after 6 times using it in a row and after having a stem cell treatment done, my hair is back to Beautiful! I will definitely continue to incorporate this product into my weekly hair maintenance routine.
KK18Hair2 days agoThank you so much for your review, Jill! 🤍 We're thrilled the Molecular Repair Hair Mask has helped restore your hair to beautiful after heat damage. We're so grateful for your trust and so happy you're making it part of your routine!
- Rachel K.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 25 - 34Hair Concern Chemical damage, Color-care, Split-Ends, Fragile/brittle hairHair Type Fine/Thin, Medium DensityMy Results Visible Difference, Stronger Hair, Less Breakage, Defined Curl/Wave PatternRated 5 out of 5 stars3 days agoEssential
As someone who dyes their hair blonde, K18 has helped it stay healthy and growing! I’m obsessed!
KK18Hair3 days agoThank you so much for your review, Rachel! 🤍 We're thrilled the Jumbo Leave-In is helping keep your blonde hair healthy and strong. We appreciate you being part of the K18 community!
- Yuliya B.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50mLI recommend this productAge 45 - 54Hair Concern Color-careHair Type Fine/ThinMy Results Visible Difference, Less BreakageRated 5 out of 5 stars4 days agoMy Hair Feels So Much Healthier
I’ve been using this hair mask for a while, and I’m really happy with the results. My hair has become more resilient and much less prone to breakage. It feels softer, smoother, and healthier, with a beautiful shine. My ends look more nourished, and my hair is much easier to brush after every use. I definitely recommend this mask, especially for damaged or color-treated hair. I’ll definitely buy it again!
KK18Hair4 days agoThank you so much for your wonderful review! 🤍 We're thrilled to hear the Molecular Repair Hair Mask is delivering such amazing results for your hair. We truly appreciate you being part of the K18 community!
- Melyssa G.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 25 - 34Hair Concern Chemical damage, Heat damage, Color-care, Fragile/brittle hair, DrynessHair Type Medium DensityMy Results Visible Difference, Stronger Hair, Less Breakage, Smoother Hair, Bouncy HairRated 5 out of 5 stars1 week agoK18 SAVED MY HAIR
This product single handily saved my hair from extreme bleach damage and breakage, I couldn’t see the end of the tunnel and my hair is finally growing again and has movement to it and retains moisture, after a bleach accident I truly never thought I would be able to see my hair this healthy again without losing my blonde, it’s almost healthier than what it used to be when it was virgin hair, it’s extremely soft and bouncy🥹 i will ALWAYS repurchase this!
KK18Hair1 week agoThank you so much for your review, Melyssa! We're absolutely thrilled to hear the Jumbo Leave-In Molecular Repair Hair Mask has helped restore your hair's health and strength. Your support means everything to us, and we're so grateful you're part of the K18 community!
- Ilena C.Verified BuyerReviewingLeave-In Molecular Repair Hair Mask Deluxe SampleI recommend this productRated 5 out of 5 stars1 week agoGreat product.
I’ve been using this product for several weeks now, and I’ve noticed my hair feels softer, smoother, and healthier. The jumbo size is a good value if you plan to use it regularly. I’m happy with the results and would recommend it to anyone looking to improve the look and feel of their hair.
KK18Hair1 week agoThank you so much for your review! We're thrilled to hear the Leave-In Molecular Repair Hair Mask has left your hair feeling softer and smoother. We truly appreciate your support and are grateful you're part of the K18 community!