K18 Leave-In Molecular Repair Hair Mask

4-minute leave-in treatment to reverse hair damage.
More info…
4.8 out of 5




About the brand

Shipping & Return Policy

A leave-in treatment mask for all hair types that clinically reverses damage in 4 minutes. The patented peptide technology works to repair damage from bleach, color, chemical services & heat – restoring strength, softness, smoothness, and bounce to hair.

Repairs damage caused by:

  • Bleach + Color
  • Chemical Services
  • Heat 
  • Mechanical Styling

Key benefits:

  • 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 bleaching treatment. Results may vary depending on hair type, quality and history.

1.  Shampoo, do not condition. Towel dry thoroughly.

2.  Begin with 1 pump of K18 Mask and add more as needed depending on the length, thickness, and condition. Work evenly into hair, one pump at a time, from ends to roots.

3.  Let sit for 4 minutes to activate.

4.  Do NOT rinse out. Style as usual.

The dos & don'ts

Do use a clarifying shampoo if you’re a heavy product or dry shampoo user.

Do dry thoroughly with hair towel or turban before application.

Do wait the full 4 minutes before styling or applying another product.

DO use every 4-6 shampoos consecutively to see and feel the full results.

DON’T condition your hair before applying K18.

DON’T use too much.

DON’T rinse it out.

K18 Mask was not formulated to work like a regular conditioner. Although some find it provides adequate softening and smoothing properties, others may prefer enhanced conditioning benefits by adding a leave-in conditioner after the four-minute processing time. 

On the days that you are not using K18 Mask, use your regular in-shower or leave-in conditioner as usual. 

If heat styling, use a heat protectant after the four-minute processing time. 

You may also layer additional styling products on top of the mask if needed.

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.

K18 is the world's first patented biotech treatment that clinically proven to reverse damage in just 4 minutes.

After spending a decade in the lab scanning and testing all amino acid sequences searching for a breakthrough within the entire keratin genome that makes up hair, K18 discovered one unique sequence that brings damaged hair back to its original, youthful state – their patented K18Peptide™ - the first product that actually heals your hair from the inside out.


Return Policy

Pro Beauty wants you to be happy with every purchase that you make.  That is why we offer a no questions asked, 30 day return policy.  We want you to feel comfortable trying a new skincare regimen, finding the right shade of foundation or figuring out which shampoo will work best for you.  

New, unopened items that are in sellable condition can be returned within 30 days of receipt for a full refund.  If the item has been used, opened or damaged,  it may be returned within 30 days of receipt for a store credit (for in store purchases) or a refund less a restocking fee (for online purchases).

To expedite the processing of a return, please bring the item in store.  If returning the item in store is not possible, please contact customer support via email at support@probeautyonline.com.  We will provide you with a free return shipping label for your item(s). 

Please note the following for all returns:

  • All returns must include all of the original components.
  • Customers must provide proof of purchase in order to be eligible for a return.
  • Perfumes are only eligible for returns if damaged during shipping.
  • Hazardous materials must be shipped USPS using ground service. 
  • Gift cards are not eligible for returns.
  • Please carefully pack returns.  Items damaged in transit are the customer's responsibility.
  • Pro Beauty reserves the right to refuse or deny any return requests or refunds at any time based on policy or program abuse.
Upon receipt of the item, please allow up to 1 week for a return to be processed, at which time a refund or gift card will be made.  


Free domestic ground shipping on all orders.  Orders placed Monday - Friday before 12PM PT will be shipped on the same business day  Orders place after 12PT or on weekends and holidays, will ship the next business day.

Expedited and international shipping is not currently available.

Restricted Hazardous Materials

Certain items considered to be hazardous materials including aerosols and alcohol-based products (i.e. pressurized cans, hair spray, mousses, nail polish, perfume, etc...) are required by the U.S. Department of Transportation to be shipped by ground only.  

All orders containing hazardous materials can only be shipped via ground to addresses within the continental U.S. and cannot be shipped to Alaska, Hawaii, U.S. territories, PO Boxes or APO/FPO addresses.


average rating 4.8 out of 5
Based on 4 reviews
  • 5 Stars
    3 Reviews
  • 4 Stars
    1 Review
  • 3 Stars
    0 Reviews
  • 2 Stars
    0 Reviews
  • 1 Star
    0 Reviews
100% of reviewers would recommend this product to a friend
Rated 5 out of 5
4 Reviews
Reviewed by Melody W.
Verified Buyer
I recommend this product
Hair Type
  • Dry Hair
  • Color Treated Hair
  • Frizz
  • Dry Hair
  • Heat Damage
Product Standouts
  • Heat Protection
  • Anti-Frizz
  • Repair Damaged Hair
  • Tame Flyaways
Rated 5 out of 5
Review posted


My hair feels soft and silky

Rated 5 out of 5
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Reviewed by Karen
I recommend this product
Rated 5 out of 5
Review posted

5 Stars

Loved it within the first application. I have tried SO many “repair” masks and none of them even compare to this one.

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Reviewed by Caroline
I recommend this product
Rated 4 out of 5
Review posted

4 Stars


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Reviewed by Jennifer T.
Verified Buyer
I recommend this product
Rated 5 out of 5
Review posted


I kept hearing about this but didn’t buy it until my hair dresser said she liked it. I trust her & it really is a great product

Rated 5 out of 5
Rated 5 out of 5
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