K18 Leave-In Molecular Repair Hair Mask 1.7 oz / 50ml

Bring damaged, stressed hair back to a stronger, smoother and healthier-looking appearance with the K18 Biomimetic Hairscience Leave-In Molecular Repair Hair Mask. Powered by the innovative K18PEPTIDE™, this leave-in treatment is designed to work at the molecular level to help reverse damage caused by bleach, color, chemical services and heat.

Unlike traditional rinse-out hair masks, K18 is a convenient leave-in treatment that works in just 4 minutes. Its lightweight formula helps restore the appearance of strength, softness, smoothness and bounce without requiring an additional rinse.

Why K18 Molecular Repair Hair Mask?

K18PEPTIDE™ is a biotech-developed biomimetic peptide designed to mimic the structure of hair and reconnect broken polypeptide chains associated with hair damage. According to K18, this process also reconnects disulfide bonds, helping reinforce hair strength along its length and width.

Key Benefits

• Helps reverse the appearance of hair damage

• Designed for damage caused by bleach and coloring

• Helps address damage associated with chemical services

• Helps repair the effects of heat damage

• Promotes stronger-feeling, smoother-looking hair

• Helps restore softness and bounce

• Lightweight leave-in formula

• Works in only 4 minutes

• No rinsing required after application

• Suitable for all hair types

• Color-safe

• Vegan and cruelty-free according to K18

How It Works

The K18 Molecular Repair Hair Mask uses K18PEPTIDE™ to work beyond the surface of the hair. The biomimetic peptide is designed to fit into hair's keratin structure and reconnect damaged polypeptide chains, supporting the hair's internal strength and resilience.

This makes it especially useful as part of a haircare routine for hair that has been exposed to repeated coloring, bleaching, chemical treatments or heat styling.

How to Use

1. Shampoo your hair and do not condition.

2. Towel-dry thoroughly.

3. Apply 1–3 pumps, depending on your hair length and density.

4. Start at the ends and work the product upward through the hair.

5. Leave on for 4 minutes.

6. Do not rinse.

7. Comb through, add styling products if desired, and style as usual.

K18 recommends using the mask for 4–6 washes after a salon service, then using it as needed.

Perfect for Damaged & Color-Treated Hair

Whether your hair has been bleached, colored, chemically treated or frequently exposed to heat styling, the K18 leave-in treatment is designed to help restore the look and feel of compromised hair.

It can be incorporated into routines for straight, wavy, curly and coily hair, with K18 stating that its molecular-level peptide technology works across all hair types.

Product Details

• Brand: K18 Biomimetic Hairscience

• Product: Leave-In Molecular Repair Hair Mask

• Size: 1.7 oz / 50ml

• Formula: Leave-in treatment

• Technology: K18PEPTIDE™

• Treatment Time: 4 minutes

• Hair Types: All hair types

• Best For: Damaged, color-treated, bleached, chemically treated and heat-stressed hair

• Application: After shampooing on towel-dried hair

• Rinse: No

• Color Safe: Yes

• Vegan: Yes

• Cruelty-Free: Yes

Why You'll Love It

✔ Professional-inspired molecular hair repair technology
✔ 4-minute leave-in treatment
✔ No rinse required
✔ Helps restore strength and resilience
✔ Helps improve softness and smoothness
✔ Ideal for damaged and processed hair
✔ Works across all hair types
✔ Convenient 1.7 oz / 50ml full-size format
✔ Powered by K18PEPTIDE™

Give your hair a smarter repair routine with K18 Leave-In Molecular Repair Hair Mask — a targeted leave-in treatment designed to help transform the look and feel of damaged hair while supporting stronger, smoother and more resilient-looking strands.