K18 Leave-In Molecular Repair Hair Mask
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.
- 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
4-minute leave-in treatment to reverse hair damage
- 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): Helps 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
- Shampoo with K18 Damage Shield PH Protective Shampoo or K18 Peptide Prep™ Detox Shampoo, do not condition. Towel-dry thoroughly
- Apply 3-9 pumps of K18 Leave-In Molecular Repair 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 consecutively for 4-6 washes post-salon service, then as needed
Frequently Asked Questions
Its patented K18PEPTIDE™ works at the molecular level to reconnect the keratin chains and disulfide bonds broken by bleach, color, chemical services, and heat — restoring strength, softness, and bounce. It’s clinically shown to repair damage in about 4 minutes.
It’s a leave-in. After shampooing (skip conditioner for this step), towel-dry, apply K18 from mid-lengths to ends, wait ~4 minutes, then style as usual — no rinsing.
Yes — it’s made for exactly that kind of damage (bleach, color, chemical straightening/rebond, and heat), and it’s sulfate-free, paraben-free, vegan, and cruelty-free.
In the shower — shampoo, but don’t condition.
Out of the shower — gently towel-dry until damp, then apply about 1 mL (a dime-sized amount) of K18 Mask. Add more only as needed; average use is around 2 mL (two dime-sized amounts), since it’s highly concentrated and you need far less than a traditional mask.
Emulsify the product on your hands before applying it on your hair (this step is very important!). After emulsifying, work it evenly through your hair from ends to roots, then wait four minutes for the K18PEPTIDE™ to reach the innermost layers. Don’t rinse it out — once the four minutes are up, style as usual (heat protectant or styling products are fine now).
How often: use it on every wash for the first four to six washes to rebuild strength, then switch to maintenance and use as needed.
Here’s a quick how-to-apply (emulsify) guide — watch the video just below.
How to Apply K18 (Emulsify)