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tile tsa-approved | color: black
4.7
Rated 4.7 out of 5 stars
8,654 Reviews

mini leave-in molecular repair hair mask

4-minute leave-in treatment to reverse hair damage
OR

Description

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 🔥 

*Disclaimers

Repairs Damage Caused By

  • Bleach + Color
  • Heat
  • Chemical Services
  1. Shampoo, do not condition. Towel-dry thoroughly.
  2. Apply 3-9 pumps of K18 leave-in molecular repair hair mask 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 product + style as usual. Use for 4-6 washes post-salon service, then as needed.
  • K18PEPTIDE™is a biotech-developed peptide that mimics hair's structure to reverse damage by reconnecting polypeptide chains and disulfide bonds broken during bleaching, color and chemical services + heat*.

  • pH-optimized (5.0-6.0) to help minimize cuticle swelling + put hair proteins in their most resilient state.

  • Cream format enables easy, lightweight application across all hair types, with detangling and softening benefits.

  • Vegan, color-safe, cruelty-free.

Takes damage repair further – reconnects both polypeptide chains (and as a result, also reconnects disulfide bonds) for strength along the length + width of the hair - offering comprehensive, lasting damage repair.

Restores hair from even extreme damage - by working at the innermost layer of the hair, core strength and elasticity are renewed for strong, smooth, bouncy hair.

Delivers immediate and lasting results – hair is repaired from the first use and lasts past your next wash, for ongoing reparative benefits.

Simplified repair - convenient, leave-in formula works in just 4 minutes, with no extra rinse required.

Works on all hair types – because K18PEPTIDE™ works on a molecular level (where all hair is the same), this product is effective on all hair types.

  • DO clarify before K18 if you’re a heavy product user (demineralize for mineral + metal buildup).
  • DO apply on clean, damp hair.
  • DO wait the full 4 minutes before combing or styling.
  • DO add whatever styling products you love after the 4 minutes.
  • DO use for 4-6 shampoos consecutively for progressive results.
  • DON'T use conditioner before applying K18 Mask (you can apply after the 4 min but most find they don’t need it).
  • DON'T overdo it—less is more.
  • DON'T rinse it out.

Water (Aqua) (Eau), Alcohol Denat., Propylene Glycol, Cetearyl Alcohol, Dicaprylyl Ether, Cetyl Esters, Behentrimonium Chloride, Polysorbate 20,sh-Oligopeptide-78 (K18PEPTIDE™), Hydrolyzed Wheat Protein, Hydrolyzed Wheat Starch, Isopropyl Alcohol, Tocopherol, Phenoxyethanol, Potassium Sorbate, Citric Acid, Fragrance (Parfum), Geraniol, Linalool, Hexyl Cinnamal, Benzyl Alcohol.

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4.8
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Weightless oil that strengthens, repairs damage + reduces frizz

Description

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 🔥 

*Disclaimers

got questions?
Get started here.
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.
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
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.
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).
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.

powered by K18PEPTIDE™

Biomimetic peptide clicks into hair’s keratin structure—the source of core strength—for soft, shiny, bouncy results that won’t wash away.

how to use molecular repair mask
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
learn more on our blog
feel what's possible with K18
See how K18 unlocks our community's expression
4.7
Rated 4.7 out of 5 stars
Based on 8,654 reviews
Reviews Summary
Customers say this leave-in hair mask transforms their hair texture and manageability after just one use. Many reviews mention noticeable improvements in softness and reduced frizz. Users with curly, fine, and color-treated hair report positive results. The mask works well for various hair types, with many noting improved texture and easier styling. While some mention the product's high price point, most find a little goes a long way. A few users recommend using conditioner alongside the mask for best results. Reviews consistently highlight the mask's effectiveness for addressing dry, brittle hair concerns.
8,654 reviews
  • Mark T.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    I recommend this product
    Age 18 - 24
    Hair Concern Chemical damage, Fragile/brittle hair, Frizz, Split-Ends
    Hair Type Fine/Thin, Medium Density
    My Results Soft Touchable Hair, Smoother Hair, Less Frizz, Visible Difference
    Rated 5 out of 5 stars
    1 hour ago
    Great Results for chemical damage

    After using the K18 repair mask, I noticed my hair was a lot less frizz, felt noticeably stronger and less prone to breakage. I truly love the results i get from this product and I hope to use it in my routine.

    K Profile picture for K18Hair
    K18Hair
    1 hour ago

    Thank you so much for your incredible review, Mark! We're absolutely thrilled to hear that our Full-Size Leave-In Molecular Repair Hair Mask is delivering such amazing results for your chemical damage - there's no better compliment than knowing our molecular repair technology is making your hair less frizzy, noticeably stronger, and less prone to breakage! We love that you're seeing such transformative results and hope it becomes a staple in your routine. ❤️

  • sheila s.
    Verified Buyer
    Reviewing
    Mini Leave-In Molecular Repair Hair Mask 15 mL
    I recommend this product
    Age 65+
    Hair Concern Chemical damage, Heat damage, Dryness, Split-Ends, Color-care
    Hair Type Fine/Thin
    My Results Visible Difference, Stronger Hair, Less Breakage, Shinier Hair, Soft Touchable Hair
    Rated 5 out of 5 stars
    3 hours ago
    Finally a product that works

    I am a retired stylist , neurotic about change ….color wise . Hair had gotten fried and dry ,k18 has started repairing my hair , after use it’s smooth healthy and shiny,

    K Profile picture for K18Hair
    K18Hair
    1 hour ago

    Thank you so much for your incredible review, Sheila! We're absolutely thrilled to hear that our Mini Leave-In Molecular Repair Hair Mask is finally the product that works for you - there's no better compliment than knowing our molecular repair technology is transforming your fried and dry hair into smooth, healthy, and shiny locks! As a retired stylist, your professional endorsement means the world to us, and we love that you're experiencing such amazing results with our treatment. ❤️

  • Ardi S.
    Verified Buyer
    Reviewing
    Leave-In Molecular Repair Hair Mask Deluxe Sample
    I recommend this product
    Rated 5 out of 5 stars
    13 hours ago
    The best hair product

    My mom’s hair used to be damaged and very difficult to manage, but since using K18 products especially the Repair Hair Mask, it has become healthy and easy to manage! My mom loves it!

    K Profile picture for K18Hair
    K18Hair
    3 hours ago

    Thank you so much for your incredible review, Ardi! We're absolutely thrilled to hear that our Leave-In Molecular Repair Hair Mask has transformed your mom's hair from damaged and difficult to manage into healthy, easy-to-manage hair that she loves - there's no better compliment than knowing our molecular repair technology is making such a meaningful difference for the special people in your life! ❤️

  • Debra C.
    Verified Buyer
    Reviewing
    Leave-In Molecular Repair Hair Mask Deluxe Sample
    I recommend this product
    Rated 5 out of 5 stars
    Yesterday
    Instant results!

    Thid mask took my hair from dry snd frizzy to smooth and manageable in one use!

    K Profile picture for K18Hair
    K18Hair
    21 hours ago

    Thank you so much for your incredible review, Debra! We're absolutely thrilled to hear that our Leave-In Molecular Repair Hair Mask Deluxe Sample delivered such instant results, taking your hair from dry and frizzy to smooth and manageable in just one use - there's no better compliment than knowing our molecular repair technology is working so effectively for you right from the start! ❤️

  • Esty S.
    Verified Buyer
    Reviewing
    Jumbo Leave-In Molecular Repair Hair Mask 100mL
    I recommend this product
    Age 18 - 24
    Hair Concern Chemical damage, Fragile/brittle hair, Frizz, Split-Ends
    Hair Type Thick/Coarse
    My Results Less Frizz
    Rated 5 out of 5 stars
    1 week ago
    THIS IS MAGIC

    I LOVE THIS SHIT IT MAKES MY HAIR LOOK AMAZING MY HAIR IS TREATED WITH A RELAXER AND WAS SO DEAD I TRIED THIS AND MY HAIR IS GORGEOUS

    K Profile picture for K18Hair
    K18Hair
    1 week ago

    Thank you so much for your incredible review, Esty! We're absolutely thrilled to hear that our Jumbo Leave-In Molecular Repair Hair Mask is working like magic on your relaxer-treated hair - there's no better compliment than knowing our molecular repair technology brought your hair back to life and made it look gorgeous again! ❤️

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