K18 hair mask bottle on a coral background with Allure award badge.

K18 biomimetic hair mask bottle with product features on a colorful background

K18 biomimetic hairscience leave-in molecular repair hair mask container on a white background

A white cylindrical bottle labeled "K18 Hair Repair, 150ml / 5 fl oz," featuring advanced peptide technology for effective hair rejuvenation.

K18 Hair Repair leave-in molecular repair mask, 15 ml bottle by K18 Hair Repair, uses peptide technology for advanced hair rejuvenation and is shown next to its pink packaging with product details.

Comparison of hair elasticity before and after using K18 PRO mist on bleached hair.

A labeled diagram of a hair strand cross-section shows polypeptide chains, intermediate filaments, macrofibrils, cortical cells, cortex, and cuticle—highlighting how K18 Hair Repair's peptide technology rejuvenates and restores hair at the molecular level.

A white bottle of K18 Hair Repair by K18 Hair Repair, a leave-in molecular repair hair mask, stands against a bright green background with award logos in the top right corner.

Multiple white K18 Hair Repair bottles are arranged on a pink gradient background with the text, "this is the future of haircare," showcasing K18 Hair Repair's advanced peptide technology for superior hair rejuvenation.

Hand applying a small amount of white cream to another hand against a neutral background

K18 hair product bottle on a pink background with text about hair care benefits.

K18 hair care product set on a pink background with 'the K18 repair routine' text.

K18 hair mask bottle with a pink and orange gradient background

Before and after comparison of a woman with curly hair using K18 mask.

Before and after comparison of hair with K18 hair care products displayed.

K18 hair care product bottles in mini, full size, and jumbo size on a pink background with a DNA strand.

K18 Hair Repair

K18 Leave-In Molecular Repair Hair Mask - Hair repair, rewritten at the molecular level.

$29.00

3 in stock

Size:

15ml / 0.5 fl oz 50ml / 1.7 fl oz 150ml / 5 fl oz

Variant

The hero of the K18 lineup — a leave-in treatment mask powered by the patented K18PEPTIDE™, a biotech-developed peptide that mimics hair's natural structure to reverse damage at the molecular level. In just four minutes, it reconnects the polypeptide chains and disulfide bonds broken by bleaching, color services, chemical treatments, and heat styling. Regular use restores strength, softness, smoothness, and bounce — making it the foundation of every K18 routine.

Results you can expect:

Clinically proven to reverse damage from bleach, color, chemical services, and heat
Reduces breakage, split ends, and color fade in just 4 minutes
Restores strength, softness, smoothness, and natural bounce
pH-optimized (5.0–6.0) to minimize cuticle swelling and keep hair proteins in their most resilient state
Lightweight cream format — easy to apply, works on all hair types
Vegan, color-safe, cruelty-free

Pickup available at Simply Colour Hair Salon Studio by Dean Downing

Usually ready in 24 hours

K18 Leave-In Molecular Repair Hair Mask - Hair repair, rewritten at the molecular level.

15ml / 0.5 fl oz

Simply Colour Hair Salon Studio by Dean Downing

Pickup available, Usually ready in 24 hours

24738 State Road 54
Lutz FL 33559
United States

+18132130959

What It Does

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.

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

Shampoo, do not condition. Towel-dry thoroughly.

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.

Let sit for 4 minutes. Do not rinse out.

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.

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.

K18 Leave-In Molecular Repair Hair Mask - Hair repair, rewritten at the molecular level.

$29.00

We clean up after ourselves.

Ecommerce deliveries have a carbon footprint. That's why we support verified projects that remove carbon from the air.

K18 Leave-In Molecular Repair Hair Mask - Hair repair, rewritten at the molecular level.

K18 Leave-In Molecular Repair Hair Mask - Hair repair, rewritten at the molecular level.

Recently viewed products