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Leave-in molecular repair hair mask 15mL
get stronger, more resilient hair. left - 8x bleach without K18, right 8x bleach with K18
get stronger, more resilient hair. left - 8x bleach without K18, right 8x bleach with K18
where K18 molecular repair works
the K18 routine
maximze your repair
less is more
works for all hair types
where does K18 fit into your routine?
K18 routine guide
4.7
Rated 4.7 out of 5 stars
7,870 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
  • 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

  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
  • 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.

pairs well with
K18 molecular repair hair oil
4.7
Rated 4.7 out of 5 stars
639 Reviews
Weightless oil that strengthens, repairs damage + reduces frizz
PEPTIDE PREP™ detox shampoo
4.8
Rated 4.8 out of 5 stars
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Color-safe, non-stripping clarifying shampoo with the K18PEPTIDE™

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.
Straight bleached hair after using K18 mask.
Straight bleached hair before using K18 mask.

healthier hair with every use

Reverse damage in 4 minutes with our breakthrough K18 molecular repair technology.
the K18 difference
Feel what’s possible with fewer steps, less waste + less time.
efficacy
patented K18PEPTIDE™ powers deeper + lasting repair.
simplicity
fewer steps for a streamlined routine.
speed
results in one 4-minute use.
how molecular repair compares
how K18 works

Traveling into the innermost layers of hair, our K18PEPTIDE™ renews strength along the width AND length of hair for lasting strength where it matters.

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 7,870 reviews
7,870 reviews
  • Rosemary M.
    Verified Buyer
    Leave-In Molecular Repair Hair Mask Sample
    Reviewing
    Leave-In Molecular Repair Hair Mask Sample
    I recommend this product
    Rated 5 out of 5 stars
    22 minutes ago
    Good stuff

    Good stuff. Makes my hair more manageable. It's easy to be thankful when your hair becomes more healthy with one single product b

  • Andrea B.
    Verified Buyer
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    I recommend this product
    Age 35 - 44
    Hair Concern Heat damage, Color-care, Dryness, Split-Ends, Frizz
    Hair Type Medium Density
    My Results Visible Difference, Less Breakage, Stronger Hair, Smoother Hair
    Rated 5 out of 5 stars
    Yesterday
    Love it

    Really makes my hair stronger and hair cut lasts longer

    K Profile picture for K18Hair
    K18Hair
    23 hours ago

    Thank you Andrea! We appreciate your review!

  • Holley O.
    Verified Buyer
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    I recommend this product
    Age 35 - 44
    Hair Concern Chemical damage, Heat damage
    Hair Type Medium Density, Straight/Wavy, Curly/Coily
    My Results Less Frizz, Less Breakage, Smoother Hair, Visible Difference, Shinier Hair
    Rated 5 out of 5 stars
    1 week ago
    So far so good!

    I noticed my hair looks much smoother after only using this product sporadically the last 2 months. I just hate not using conditioner after my shampoo .. that is why I have not used it as directed. Looking at my photos I need to give it a good try. Will upate after using it the next feq weeks consistently!

    K Profile picture for K18Hair
    K18Hair
    4 days ago

    Thank you Holley! You can use conditioner after the mask has been applied and the 4 minutes have surpassed.

  • gabs g.
    Verified Buyer
    Mini Leave-In Molecular Repair Hair Mask 15 mL
    Reviewing
    Mini Leave-In Molecular Repair Hair Mask 15 mL
    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 Less Breakage, Smoother Hair, Soft Touchable Hair
    Rated 5 out of 5 stars
    1 week ago
    Excellent

    Had chemically damaged hair, I have seen k18 replenish my hair by making it softer and less brittle.

    K Profile picture for K18Hair
    K18Hair
    1 week ago

    Wow look at that lovely hair! Thank you Gabs for your 5-star review!

  • Diana G.
    Verified Buyer
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50mL
    I recommend this product
    Age 45 - 54
    Hair Concern Chemical damage
    Hair Type Medium Density
    My Results Visible Difference
    Rated 5 out of 5 stars
    4 weeks ago
    Lo mejor este producto

    Me encanta es mi segundo fresco, compré el pequeño y me encanto por eso compré el más grande I love

    K Profile picture for K18Hair
    K18Hair
    4 weeks ago

    ¡Gracias Diana! ¡Nos encanta saber que estás disfrutando de tu mascarilla K18 Molecular Repair!

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