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.
20+ billion TikTok views 🔥
Get started here.
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
- Appearance
- Value
- Erika G.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 35 - 44Hair Concern Chemical damage, Dryness, Fragile/brittle hairHair Type Thick/CoarseMy Results Visible Difference, Less Breakage, Smoother Hair, Soft Touchable Hair, Stronger HairRated 5 out of 5 stars4 minutes agoA magic treatment
I saw changes from the first time I used it.
- Oliviah M.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50mLI recommend this productAge 18 - 24Hair Concern Chemical damage, Color-care, Dryness, Split-EndsHair Type Straight/Wavy, Medium DensityMy Results Visible Difference, Soft Touchable Hair, Smoother Hair, Less FrizzRated 5 out of 5 stars9 hours agoWorked very well!
I really really enjoyed the product! I have bleached my hair maybe 6 times this past year and it’s brought my hair back to life!
KK18Hair9 hours agoThank you so much for the love! 💙 We're thrilled to hear that the Leave-In Molecular Repair Hair Mask has brought your hair back to life! It's amazing to know it's making such a difference for you. We're so grateful you're enjoying it! ✨
- Karen F.Verified BuyerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 65+Hair Concern Chemical damageHair Type Medium DensityMy Results Stronger Hair, Less Breakage, Less Frizz, Shinier Hair, Soft Touchable HairRated 5 out of 5 stars9 hours agoK18 Saved my hair!
I found out about K18 approximately 4yrs ago after I had massive damage from a perm. I know I should have known better, but another story. I was wearing baseball hats and I was ready to shave my head. The first time I used it on my hair I was sold and have been a huge fan. The jumbo 100ml takes the pressure out of constantly ordering the smaller bottle. I love it.
KK18Hair9 hours agoThank you so much for sharing your love for K18! 💙 We're absolutely thrilled to hear that our Jumbo Leave-In Molecular Repair Hair Mask has been such a game-changer for you over these past 4 years. Your loyalty means the world to us, and we're so glad the larger 100ml size takes the pressure off and keeps you stocked up. We love being part of your hair journey! ✨
- chrystine k.Verified BuyerReviewingLeave-In Molecular Repair Hair Mask Deluxe SampleI recommend this productRated 5 out of 5 stars14 hours agoThe Goat
This is my holy grail. It keeps my long hair from snapping off.
KK18Hair13 hours agoThank you so much for the love! 💙 We're thrilled to hear the Leave-In Molecular Repair Hair Mask is your holy grail! ✨
- AprilReviewingMini Leave-In Molecular Repair Hair Mask 15 mLRated 3 out of 5 stars18 hours ago3 Stars
It works alright. Glad I purchased the small size so I could try it. Sadly it is ok. It does not work as advertised. Maybe over time?
KK18Hair10 hours agoThank you for giving K18 a try and for sharing your honest feedback! 💙 We understand that results may not feel immediate, and consistent use is key to seeing the full benefits of the Molecular Repair Hair Mask. We appreciate you starting with the smaller size and hope you’ll continue to see improvements with continued use! Reach out to us via email so we can troubleshoot to get you results you will love.