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Leave-in molecular repair hair mask 50mL
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
full size leave-in molecular repair hair mask- 50 does per bottle.
Before and after image using detox, mask, conditioner, and oil
highly concentrated formula = a little goes a long way
Curly hair before using K18 mask and curly hair after using K18 mask.
full size leave in mask- start with 1 pump add more as needed. Mini size mask- start with 3 pumps add more as needed.
Clinically proven to reverse damage from: bleach + color, chemical services, and heat.
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Where does K18 fit into your routine? 1. Shampoo (skip conditioner) 2. Towel dry 3. K18 4. wait for minutes 5. everything else
Leave-in molecular repair hair mask 50mL
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
full size leave-in molecular repair hair mask- 50 does per bottle.
Before and after image using detox, mask, conditioner, and oil
highly concentrated formula = a little goes a long way
Curly hair before using K18 mask and curly hair after using K18 mask.
full size leave in mask- start with 1 pump add more as needed. Mini size mask- start with 3 pumps add more as needed.
Clinically proven to reverse damage from: bleach + color, chemical services, and heat.
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Where does K18 fit into your routine? 1. Shampoo (skip conditioner) 2. Towel dry 3. K18 4. wait for minutes 5. everything else
4.9
Rated 4.9 out of 5 stars
2,265 Reviews
bestseller

full-size leave-in molecular repair hair mask

Retail size of our 4-minute leave-in treatment to reverse hair damage

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description

A retail-sized version of the K18 mask helps to maintain your client's hair strength and elasticity in-between salon appointments. This leave-in treatment mask for all hair types that reverses damage in 4 minutes. Patented peptide technology works to repair damage from bleach + color, chemical services, and heat* — restoring strength, softness, smoothness, and bounce to hair.


20+ billion TikTok views 🔥 


*Disclaimers

Repairs Damage Caused By

Bleach + Color

Heat

Chemical Services

    • more to know

      Takes damage repair further – biomimetic peptide seamlessly fits in and reconnects 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 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 and with every service

    • key benefits
      • 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, and heat*.
      • pH-optimized (5.0-6.0) to help minimize cuticle swelling + put hair proteins in their most resilient state after salon service or shampoo
      • Cream format enables easy, lightweight application across all hair types, with detangling and softening benefits.
      • Vegan, color-safe, cruelty-free
    • how to use
      1. Shampoo, do not condition. Towel-dry thoroughly
      2. Apply 1-3 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
    • 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.

pairs well with
molecular repair hair oil
View Product
PEPTIDE PREP™ detox shampoo
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Leave-in molecular repair hair mask 50mL
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
full size leave-in molecular repair hair mask- 50 does per bottle.
Before and after image using detox, mask, conditioner, and oil
highly concentrated formula = a little goes a long way
Curly hair before using K18 mask and curly hair after using K18 mask.
full size leave in mask- start with 1 pump add more as needed. Mini size mask- start with 3 pumps add more as needed.
Clinically proven to reverse damage from: bleach + color, chemical services, and heat.
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Where does K18 fit into your routine? 1. Shampoo (skip conditioner) 2. Towel dry 3. K18 4. wait for minutes 5. everything else
Leave-in molecular repair hair mask 50mL
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
Before and after using k18 professional leave in hair mask and professional hair mist.
full size leave-in molecular repair hair mask- 50 does per bottle.
Before and after image using detox, mask, conditioner, and oil
highly concentrated formula = a little goes a long way
Curly hair before using K18 mask and curly hair after using K18 mask.
full size leave in mask- start with 1 pump add more as needed. Mini size mask- start with 3 pumps add more as needed.
Clinically proven to reverse damage from: bleach + color, chemical services, and heat.
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
Where does K18 fit into your routine? 1. Shampoo (skip conditioner) 2. Towel dry 3. K18 4. wait for minutes 5. everything else
got questions?

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.

soft, strong, bouncy hair for everyone

Repair damage for hair like new* in 4 minutes.

before afer
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after
"I absolutely love this product!! You have to see it to believe it!"
- Christina Marie P.
before afer
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after
“…I had my hair chopped (it was begging for it) along with some highlights and coloring of the roots. My hair stylist used this on my hair and I absolutely loved how it made my hair feel ... I love this mask so much!”
- Ashley P.
before afer
before
after
"Amazing the way it feels and the shine provides to the hair instantly."
- Sandra M.
before afer
before
after
"I’ve been using this mask for about four washes so far. I feel that my hair is getting healthier."
- Olga S.
before afer
before
after
"It makes my hair so soft and weightless, I absolutely love it... Makes my hair feel so luxurious, it’s like I just left the salon. Can’t recommend this product more!"
- Anastasiia T.
before afer
before
after
"My hair has been a mess for years... My new hair stylist recommended K18! ... My hair looks and feels amazing with lasting results!!"
- Arnell M
before afer
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after
"I have heat damaged color treated curly hair and this has improved my hair health immensely...This is one of those products that has incorporated itself into my routine for the rest of my life..."
- Siria A.
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.

Explore the Science EXPLORE THE SCIENCE
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.


*k18hairpro.com/disclaimers

learn more on our blog
How to Use the K18 Mask Correctly Step-by-Step
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How to Use the K18 Mask Correctly Step-by-Step
It’s easier (and faster) than you think
about How to Use the K18 Mask Correctly Step-by-Step
How to Explain the K18 Mask to Clients So They Actually Get It
/ products
How to Explain the K18 Mask to Clients So They Actually Get It
Breaking down real hair science (without ruining the vibe)
about How to Explain the K18 Mask to Clients So They Actually Get It
The Top K18 Mask FAQs
The Top K18 Mask FAQs
answering your most-asked questions.
about The Top K18 Mask FAQs
How much leave-in mask should you use?
/ products
How much leave-in mask should you use?
A handy dosage guide for every hair type, density, and length.
about How much leave-in mask should you use?
When Should I Use K18 Conditioner vs. Mask?
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When Should I Use K18 Conditioner vs. Mask?
Get the guide to repairing and protecting every client’s hair.
about When Should I Use K18 Conditioner vs. Mask?
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feel what's possible with K18

See how K18 unlocks our community's expression

4.9
Rated 4.9 out of 5 stars
Based on 2,265 reviews
97%would recommend these products
Customers Talked About
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2,265 reviews
  • Rocio R. U.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
    I recommend this product
    Age 25 - 34
    Hair Concern Chemical damage, Dryness, Split-Ends, Fragile/brittle hair, Extending time between washes
    Hair Type Medium Density
    My Results Less Frizz, Visible Difference, Stronger Hair, Less Breakage, Shinier Hair
    Rated 5 out of 5 stars
    2 days ago
    It works wonders

    I relax my hair so it is pretty damaged, I have used this 3 times and I already feel a difference. My hair feels stronger, it leaves your hair shiny and soft.

    Was this helpful?
    K18Hair PRO
    2 days ago

    Thank you so much for sharing, Rocio! We're thrilled to hear the Molecular Repair Hair Mask is making such a positive difference for your hair. We love knowing it's leaving your strands feeling stronger, shinier, and softer! 💕

  • Jill D.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
    I recommend this product
    Age 55 - 64
    Hair Concern Heat damage, Chemical damage, Frizz, Fragile/brittle hair
    Hair Type Thick/Coarse, Straight/Wavy
    My Results Visible Difference, Soft Touchable Hair, Less Breakage, Less Frizz, Stronger Hair
    Rated 5 out of 5 stars
    1 week ago
    Love 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.

    Was this helpful?
    K18Hair PRO
    1 week ago

    Thank 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!

  • Yuliya B.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
    I recommend this product
    Age 45 - 54
    Hair Concern Color-care
    Hair Type Fine/Thin
    My Results Visible Difference, Less Breakage
    Rated 5 out of 5 stars
    1 week ago
    My 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!

    Was this helpful?
    K18Hair PRO
    1 week ago

    Thank 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!

  • Deb M.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
    I recommend this product
    Age 45 - 54
    Hair Concern Chemical damage, Heat damage, Color-care, Dryness, Split-Ends
    Hair Type Fine/Thin
    My Results Less Frizz, Smoother Hair
    Rated 5 out of 5 stars
    3 weeks ago
    Magical!

    Love everything about this product

    Was this helpful?
    K18Hair PRO
    3 weeks ago

    Thank you so much for your amazing review! 💛 We're thrilled to hear you're loving our Full-Size Leave-In Molecular Repair Hair Mask. Your support means the world to us! ✨

  • Amrita S.
    Verified Buyer
    Reviewing
    Full-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)
    I recommend this product
    Age 25 - 34
    Hair Concern Heat damage, Chemical damage, Fragile/brittle hair
    Hair Type Fine/Thin
    My Results Stronger Hair, Less Breakage
    Rated 5 out of 5 stars
    3 weeks ago
    Instant difference

    I have very poor quality hair postpartum which break so often. I have used K18 and in a week the breakage has reduced substantially. I had also done keratin sometime ago and needless to say K18 is slowly overturning the damage.

    Was this helpful?
    K18Hair PRO
    3 weeks ago

    Thank you so much for your amazing review, Amrita! 💛 We're thrilled to hear the Leave-In Molecular Repair Hair Mask is helping reduce breakage and restore your hair's health. Here's to stronger, healthier hair days ahead! ✨

*Disclaimers