K18 Leave-In Molecular Hair Mask, Repairs Dry or Damaged Hair, Reverse Hair Damage from Bleach, Color, Chemical Services & Heat

K18 Leave-In Molecular Hair Mask, Repairs Dry or Damaged Hair, Reverse Hair Damage from Bleach, Color, Chemical Services & Heat

 (51,669 Reviews)
$115.90
$115.90 $135.90
Sold out

BUNDLE & SAVE

A leave-in treatment mask that works on the molecular level to reverse hair damage in just 4 minutes. The  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.

Bleach + Color

Heat

Chemical Services

View full details

jumbo leave-in molecular repair hair mask

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 🔥 

Repairs Damage Caused By

Bleach + Color

Heat

Chemical Services

more to know

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.

key benefits

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.

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.

dos and don'ts

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.

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.

Real people, real results

"I absolutely love this product!! You have to see it to believe it!"- Christina Marie P.

Before

After

 
 

Amazing the way it feels and the shine provides to the hair instantly" -Sandra M.

Before

After

 
 
 
  •  

    Powered by K18PEPTIDE

    Biomimetic peptide bonds with hair’s keratin structure—the source of its core strength—for soft, shiny, and 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.

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    powered by biotech /feel what's possible with hair like new, 

    Customer reviews

    Best for damage repairIt wides wonders to the hair

    Tina B.

    VERIFIED PURCHASE

    Loving my Hair with Molecular RepairLove it makes my hair shine and it behaves wonderfully

    Ann M. R.

    VERIFIED PURCHASE

    Leave in Hair MaskAmazing product!! I have many fine hair most products weigh it down or matter it fuzzy! This product dues neither best thing I have found!!!

    Theresa M. M.

    VERIFIED PURCHASE

    Major differenceI got a bad bleached job not too long ago and my hair was so damaged. I had to cut so much off. It made me very sad.. even after a haircut, I felt like more could have been cut off because of the damage. However, since I started using this product once a week, I have noticed significant repairing in my hair ! This is for sure, a staple product for me. I no longer waste my money on the cheap alternatives when this is the only thing on the market with its repairing technology.. !

    Kellie D.

    VERIFIED PURCHASE

    Leave in Hair MaskAmazing product!! I have many fine hair most products weigh it down or matter it fuzzy! This product dues neither best thing I have found!!!

    Theresa M. M.

    VERIFIED PURCHASE

    I love this stuff!I have been using this for years and will forever keep using it. I recommend to everyone!

    Hailey B.

    VERIFIED PURCHASE

    Best for damage repairIt wides wonders to the hair

    Tina B.

    VERIFIED PURCHASE

    Loving my Hair with Molecular RepairLove it makes my hair shine and it behaves wonderfully

    Ann M. R.

    VERIFIED PURCHASE

    Leave in Hair MaskAmazing product!! I have many fine hair most products weigh it down or matter it fuzzy! This product dues neither best thing I have found!!!

    Theresa M. M.

    VERIFIED PURCHASE

    Major differenceI got a bad bleached job not too long ago and my hair was so damaged. I had to cut so much off. It made me very sad.. even after a haircut, I felt like more could have been cut off because of the damage. However, since I started using this product once a week, I have noticed significant repairing in my hair ! This is for sure, a staple product for me. I no longer waste my money on the cheap alternatives when this is the only thing on the market with its repairing technology.. !

    Kellie D.

    VERIFIED PURCHASE

    Leave in Hair MaskAmazing product!! I have many fine hair most products weigh it down or matter it fuzzy! This product dues neither best thing I have found!!!

    Theresa M. M.

    VERIFIED PURCHASE

    I love this stuff!I have been using this for years and will forever keep using it. I recommend to everyone!

    Hailey B.

    VERIFIED PURCHASE

    FAQS

    What makes this “jumbo” 100 mL size different from the regular size?

    The formula is the same: it uses the patented K18 “K18PEPTIDE™” technology to reverse hair damage in just 4 minutes. K18Hair+2K18Hair+2

    The “jumbo” designation simply refers to the larger 100 mL volume—ideal if you use the treatment regularly or have long / dense hair.

    How should I apply this mask, and how often?

    • After shampooing (and skipping conditioner at this step), apply a small amount of the mask to towel-damp hair.
    • Let the product sit for 4 minutes. You do not rinse it out.
    • After the 4-minute activation, you may apply your regular conditioner or other styling products if desired.
    • For hair that’s been heavily damaged (bleach, color, chemical, heat), initial use might be with every wash for several washes in a row, then taper to maintenance use. (This is the recommended routine for the standard size and applies with the jumbo as well.)

    What kinds of hair damage does it address?

    This mask targets internal damage (broken polypeptide chains, disulfide bonds) caused by:

    • Bleaching & color services (hair lightening)
    • Chemical treatments (relaxers, perms)
    • Heat styling and mechanical stress (straighteners, curling irons, blow-drying)

      Because the action is at a molecular level, the brand states it works on all hair types.

    Will my hair feel heavy or coated after using it?

    According to the brand, no. Since the mask is leave-in but formulated to penetrate rather than simply coat the hair surface, you shouldn’t feel a heavy film. The key is: skip conditioner at the same time step as the mask—because conditioner film can block the peptide’s penetration.

    Some users have noted that their hair felt stiffer if they over-applied or used on hair that wasn’t sufficiently damaged (protein overload).

    So use the appropriate amount (based on your length and density) and monitor how your hair responds.