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leave-in molecular repair hair mask

4-minute leave-in treatment to reverse hair damage
Rated 4.7 out of 5
Based on 2197 reviews

An at-home leave-in treatment infused with our patented K18Peptide™ that works to repair even the most extreme damage, renewing hair to its most youthful, healthy state. 


K18 products are Certified Plastic Neutral by Plastic Bank.


 

Repairs Damage Caused By

  • Bleach + Color Bleach + Color
  • Heat Heat
  • Chemical Services Chemical Services
FREE SHIPPING. FREE RETURNS.

more to know

creates hair like new
Traveling deeper into the inner layers of hair than traditional repair products, our revolutionary patented K18Peptide™ is just the right size and makeup to fit in and reconnect broken keratin chains, renewing hair with strength, softness, smoothness, and bounce. You can feel and see the difference with the first use.

See dosage chart for exact usage. For best results, use for the first 4-6 consecutive washes, then every 3-4 washes as needed to maintain hair strength.

how to use

IN the shower

  1. Shampoo, do not condition.

OUT of the shower

  1. Towel dry thoroughly.
  2. Begin with 1 pump of the K18 Mask and add more as needed depending on the length, thickness, and condition.
  3. Work evenly into hair from ends to roots, one pump at a time.
  4. Let sit for 4 minutes to activate.
  5. Do NOT rinse out.
  6. Style as usual.

Dosage Guide:

do's + don'ts

  • DO use a clarifying shampoo if you’re a heavy product or dry shampoo user to remove buildup and help our peptide penetrate and get where it needs to go.
  • DO wait the full 4 minutes before styling or applying other product
  • DO use every 4-6 shampoos consecutively to see and feel ongoing results
  • DON’T condition your hair before application (trust us, most won’t need it after K18, if you still need, add a leave-in after the 4-minute window is up post-application)
  • DON’T overuse, a little goes a long way.
  • DON’T rinse out. This is a leave-in, so you know, leave it in!

key benefits

Our K18Peptide™ is clinically proven to reverse damage in just 4 minutes.

  • Heals damage from bleach, color, chemical services, and heat
  • Restores strength, softness, smoothness, and bounce
  • Doesn’t wash away with shampoo, leaving lasting results
  • Vegan, color-safe, cruelty-free

up to 91% original strength*
up to 94% original elasticity*

* Results observed in a clinical study while using mist and mask as part of a bleaching treatment. Results may vary depending on hair type, quality and history.

ingredients

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.

Description

An at-home leave-in treatment infused with our patented K18Peptide™ that works to repair even the most extreme damage, renewing hair to its most youthful, healthy state. 


K18 products are Certified Plastic Neutral by Plastic Bank.


 

what you can expect
by damage type

backed by science,
loved by stylists

Our community of stylists and colorists believe K18 is liberating hair—no matter the hair type or generation.

“K18 allows me to go everywhere I want to go with my color work and the end result is my guests get to be bright and shiny and healthy.”

– Christine Thompson, Director of Color at Spoke & Weal

have questions?

we have answers.

How does K18 work?

When hair gets damaged, the polypeptide chains (keratin chains) that make up the inner structure of hair strands become weakened and break. For context, there are billions and billions of polypeptide chains (keratin chains) in a single strand of hair. When these are damaged, hair’s core structure responsible for elasticity and strength becomes compromised and as a result it loses its resiliency and shine—or the look and feel of healthy hair.

After spending a decade in the lab scanning and testing all amino acid sequences across the entire keratin genome that makes up human hair searching for a breakthrough, we discovered one unique sequence (a bioactive peptide) that brings damaged hair back to its original, youthful state. This is our K18Peptide™.

Traveling deeper into the inner layers of hair than traditional repair products, our revolutionary peptide is just the right size and makeup to fit in and reconnect those broken polypeptide chains (keratin chains). And because our peptide is a bit of an overachiever, as a result of this reconnection, any disturbed disulfide bonds are also re-conformed.

Our peptide employs biomimetics to get the job done. To put it simply: Biomimetics is the practice of learning from and mimicking nature. Mimicking the natural structure of keratin building blocks (amino acid sequences), our K18 bioactive peptide is recognized as natural by the hair. It’s not washed away by water or shampoo like traditional bonding agents either, making K18 a genuine, lasting solution for damaged strands.

What is the K18Peptide™?

Our patented peptide is a unique sequence of amino acids that travels deep into hair’s core structure to fit in and reconnect broken polypeptide chains (keratin chains) responsible for hair strength and elasticity.

An Analogy: When building proteins, the order of the amino acids determines the kind of protein and its properties, much like the way letters are arranged to make meaningful words and sentences. In the same way the order and where each word sits in a sentence leads to its overall meaning, K18 is the magic word that fits right in, integrating itself with the keratin chains as the hair recognizes it as a natural building block.

Why should I skip conditioner?

K18 is most effective on clean, towel-dried hair. Conditioners use silicones and conditioning agents that form heavy coatings on hair, preventing our peptide from reaching the broken polypeptide chains deep inside hair’s inner layer.

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. Our unique blend of 3 alcohols function to open up the hair cuticle so the K18Peptide ™ can penetrate the inner most layer of hair, reaching the broken polypeptide chains (keratinchains). Here the alcohol serves as an agent to optimize the hair environment for K18 to work on a deeper level.

When should I expect to see results?

You will start to see stronger, softer, healthier hair after just one use.
0%
original strength*
0%
original elasticity*
with just one salon treatment, hair is restored up to
* Results observed in a clinical study while using mist and mask as part of a bleaching treatment. Results may vary depending on hair type, quality and history.
when using K18 mist and mask as part of a bleaching treatment
*Results observed in a clinical study. Results may vary depending on hair type, quality, and history.
the more damaged the hair, the more dramatic the results
*Results observed in a clinical study. Results may vary depending on hair type, quality, and history.

renews strength, softness, smoothness, and bounce

K18 strengthens hair’s core structure, restoring damaged curl patterns and leaving strands looking and feeling like new.
K18 reconnects broken keratin chains, restoring hairs elasticity and strength meaning coily hair can be renewed and brought back to its original springy, healthy shape.
K18 restores strength, softness, smoothness, and bounce so even the sleekest hair can feel like new.
Reviews
average rating 4.7 out of 5
Based on 2197 reviews
  • 5 Stars
    1824 Reviews
  • 4 Stars
    206 Reviews
  • 3 Stars
    86 Reviews
  • 2 Stars
    38 Reviews
  • 1 Star
    43 Reviews
93% of reviewers would recommend this product to a friend
Customer photos and videos
2197 Reviews
Reviewed by Kiki T.
Verified Buyer
I recommend this product
Age
18 - 24
Hair Concern
  • Chemical damage
  • Dryness
  • Color-care
Hair Type
  • Thick/Coarse
  • Straight/Wavy
My Results
  • Visible Difference
  • Stronger Hair
  • Less Breakage
  • Soft Touchable Hair
Rated 5 out of 5
Review posted

Bleached Hair Feels like Normal Hair

I recently got my hair bleached all the way to platinum, but by using K18 it feels like my hair has never been touched by bleach! Wonderful product that’s definitely worth it for bleached hair, though it does not do anything for my non-bleached hair.

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Reviewed by Krysta S.
Verified Buyer
I recommend this product
Age
25 - 34
Hair Concern
  • Chemical damage
  • Heat damage
  • Frizz
  • Dryness
  • Fragile/brittle hair
Hair Type
  • Thick/Coarse
My Results
  • Less Frizz
  • Visible Difference
  • Bouncy Hair
  • Smoother Hair
  • Soft Touchable Hair
Rated 5 out of 5
Review posted

LOVE IT!!!!!

This stuff is like magic makes my hair so soft and smooth it's unbelievable I will continue using for sure

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Reviewed by norma v.
Verified Buyer
I recommend this product
Age
25 - 34
Hair Concern
  • Chemical damage
Hair Type
  • Fine/Thin
My Results
  • Smoother Hair
  • Soft Touchable Hair
Rated 4 out of 5
Review posted

Good for your hair

even tho I don’t use conditioner when I apply k18 my hair still feels super soft. My hair is super damaged but I’ve seen some improvement (I gotta add I’m also using other products to bring it back to life).

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K18Hair

Thank you for your review Norma!

Reviewed by Quaan
Verified Buyer
I recommend this product
Age
35 - 44
Hair Concern
  • Dryness
  • Frizz
  • Heat damage
  • Chemical damage
  • Color-care
Hair Type
  • Grey Hair
  • Straight/Wavy
  • Thick/Coarse
  • Medium Density
  • Fine/Thin
My Results
  • Shinier Hair
  • Smoother Hair
  • Less Breakage
  • Stronger Hair
  • Visible Difference
Rated 5 out of 5
Review posted

Love it

I used the k18 leave in on a few of my clients that was having trouble with hair breakage and heat damage. I could tell the difference in there hair Immediately. It felt stronger. It's a must have for me

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K18Hair

Thank you for your awesome review Quaan!

Reviewed by Tammy Sofia C.
Verified Buyer
I recommend this product
Age
55 - 64
Hair Concern
  • Heat damage
  • Color-care
  • Frizz
  • Dryness
  • Split-Ends
Hair Type
  • Straight/Wavy
My Results
  • Less Frizz
  • Less Breakage
  • Smoother Hair
  • Soft Touchable Hair
  • Visible Difference
Rated 5 out of 5
Review posted

Amazing Stuff

I’ve struggled for years with frizzy, damaged hair. This is the only product that has really helped, and it did so after a single application. I’m hooked!

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K18Hair

Thank you for your review Tammy!

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leave-in molecular repair hair mask

Rated 4.7 out of 5
Based on 2197 reviews
4-minute leave-in treatment to reverse hair damage
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Pro Distribution Partners

Hair professionals can shop wholesale at the following distributors. Professionals within the US will also be able to shop directly from K18hair.com starting early 2021! Check back again soon for updates as we continue to expand globally.



Questions? Email us at hello@k18hair.com

Paramount Beauty Supply

USA

Salon Services Pro

USA

Salon Service Group

USA

Salonwax Pro

USA

Premier Beauty Supply

USA
Launching Soon

Ozdare - Australia

AU
 
Launching Soon

American Crew Ltd. - New Zealand

NZ
 
Launching Soon

PlayGround - Hong Kong

HK
 
Launching Soon

Session Map - Sweden

SE
 
Launching Soon

Cyprus

CY
 
Launching Soon

Belgium

BE
 
Coming Early 2021

Canada

CA
 
Coming Early 2021

Czech Republic

CZ
 
Coming Early 2021

Finland

FI
 
Coming Early 2021

France

FR
 
Coming Early 2021

Germany

DE
 
Coming Early 2021

Ireland

IR
 
Coming Early 2021

Italy

IT
 
Coming Early 2021

Netherlands

NL
 
Coming Early 2021

Norway

NO
 
Coming Early 2021

Singapore

SG
 
Coming Early 2021

Taiwan

TW
 
Coming Early 2021

UK

UK
 
Coming Early 2021

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