K18 is one of the most talked-about professional haircare innovations of the decade — a brand built on a single, breakthrough ingredient: the K18Peptide™. This patented biomimetic peptide was engineered to reconnect broken polypeptide chains in the hair's inner cortex, the damage type that most other bond-builders, proteins, and treatments simply can't reach.
Unlike multi-step systems, K18 requires just 4 minutes of leave-in time on clean, towel-dried hair to deliver results. Clinical tests show that K18 reverses up to 91% of chemical damage, 79% of bleach damage, and significant mechanical and heat damage — results that once required weeks of intensive treatment protocols.
At ProHair.ca, K18 is the brand we recommend for clients who want the most efficient, scientifically validated professional repair available today. One treatment per wash is all it takes.
K18 Lines We Carry
Here's a breakdown of every K18 line available at ProHair.ca and what it's best for:
K18 Leave-In Molecular Repair Hair Mask
The hero product. 4-minute leave-in that uses K18Peptide™ to reconnect broken polypeptide chains. No rinse required.
K18 Peptide Prep Shampoo
Sulphate-free prep shampoo formulated to cleanse and prepare hair for maximum K18 peptide absorption.
K18 Mist
Lightweight leave-in mist for daily K18Peptide™ maintenance — a micro-dose of repair for everyday use.
K18 Color Shield
Colour protection shampoo that maintains vibrancy while delivering daily maintenance-level peptide benefits.
Who Is K18 For?
- Bleached or highlighted hair -> K18 Leave-In Molecular Repair Mask (91% chemical damage reversal)
- Heat-damaged hair -> K18 system (79% heat damage reversal)
- Colour-treated -> K18 Peptide Prep (pre-colour bond prep)
- All damage types -> One K18 leave-in covers all four damage types
Best K18 Products to Explore
Molecular Repair Treatments
K18Peptide™-powered treatments that reconnect broken polypeptide chains in just 4 minutes.
Prep & Cleansing
Sulphate-free shampoos designed to maximise peptide absorption and colour safety.
Daily Maintenance
Mist and lightweight products for daily K18 peptide top-ups between full mask applications.
Frequently Asked Questions
How is K18 different from Olaplex?
K18 and Olaplex both repair damaged hair but target different bond types. Olaplex reconnects disulphide bonds (SS bonds) broken during oxidative processes. K18Peptide™ reconnects broken polypeptide chains in the hair's inner cortex — a different repair mechanism that Olaplex doesn't address. Many professionals use both.
How often should I use K18?
For damaged hair, every wash is recommended. Once hair is restored, once a week or every few washes is sufficient for maintenance.
Does K18 work on colour-treated hair?
Yes. K18 is safe for all colour-treated hair and can be used after colour services to repair any damage from the colouring process.
Why is K18 only 4 minutes?
The K18Peptide™ is engineered to rapidly penetrate the hair cortex. In clinical tests, 4 minutes was sufficient for the peptide to fully absorb and begin reconnecting broken polypeptide chains.
Can I use K18 with other treatments?
Yes. K18 is compatible with other professional treatments. Apply K18 Leave-In after shampooing, wait 4 minutes, then proceed with styling. Do not rinse off.
Shop K18 at ProHair.ca
ProHair.ca is an authorized Canadian retailer of K18 professional products. Browse the full collection with free shipping on orders over $99.99.