Both K18 and Olaplex repair bleached hair, but they work in different ways. Olaplex rebuilds the broken bonds inside the hair that bleach breaks down. K18 uses a patented peptide that repairs damaged keratin chains, restoring strength, softness and bounce. If your hair feels weak and snaps easily, both help. If it feels dry, rough and straw-like, K18 is usually the faster fix.
How does Olaplex work?
Olaplex's patented technology reconnects broken bonds inside the hair, the ones that lightening, colour and heat break. At home, Olaplex No.0 is a bond-building primer you apply before shampooing, and No.7 Bonding Oil is a weightless styling oil that adds shine and softness.
How does K18 work?
K18's peptide, K18PEPTIDE, works inside the hair to repair damage from bleach, colour, chemical services and heat. The Molecular Repair Hair Mask is a 4-minute leave-in: you apply it to towel-dried hair, wait, and style as usual with no rinse.
Which is better for bleached hair?
- Choose K18 if your hair has lost its softness and bounce, tangles easily, or feels rough after lightening. Many people notice a difference after one use.
- Choose Olaplex if your hair breaks or snaps when you brush it, or you're between lightening appointments and want to keep strengthening it.
- Not sure? Ask your stylist at your next visit. We can look at your hair and recommend one.
Can you use K18 and Olaplex together?
Yes. They work differently, so they don't cancel each other out. A simple routine: Olaplex No.0 before shampooing once a week, the K18 mask every 4 to 6 washes, and a few drops of Olaplex No.7 or K18 Molecular Repair Hair Oil on damp ends before styling.
The complete repair regimen
Our K18 Damage Repair Bundle puts the whole routine together: Damage Shield shampoo and conditioner, the Molecular Repair Mask, Hair Oil and AirWash dry shampoo. It's $300, compared with $380 if you buy each product separately. See everything for damaged hair in our Damaged Hair collection.
Frequently asked questions
How often should I use the K18 mask?
Every 4 to 6 washes, or whenever your hair feels like it needs it.
Do I need to rinse K18 out?
No. It's a leave-in. Leave it on for 4 minutes, then style as usual.
Where can I buy K18 and Olaplex in Toronto?
At Tempt(d) Studio, 220 Bloor St W in Yorkville, or online with free shipping in Canada on orders over $90.