K-18 at Maven Salon: What Molecular Repair Does for Damaged Hair
TL;DR: K-18 is a leave-in peptide treatment that works inside the hair shaft, reconnecting the broken keratin chains that make damaged hair feel weak and stretchy. We use it in the chair as part of our treatment services and send guests home with it after big color work. It repairs, where most masks just coat.
What is K-18, in plain English?
Most conditioners and masks work on the outside of your hair. They smooth the cuticle, add slip, and make hair feel better until the next wash. K-18 is different: it's a small peptide that gets inside the hair shaft and reconnects the keratin chains that break when hair is lightened, heat-styled, or chemically treated.
That inside-versus-outside difference is why we treat it as its own category on the hair treatments page. A smoothing service changes how your hair behaves. A gloss changes how it looks. K-18 changes how it holds together.
How do we use it at the salon?
Two ways:
- In the chair. As a treatment during color services, especially lightening. If we're brightening you up, this is the insurance that your hair still feels like hair afterward.
- At home. The leave-in mask, used on wash days after bigger chemical work. It's on our retail shelf, and it's one of the products we actually reach for rather than just stock. You'll find our current favorites on the favorite products page.
Who actually needs it?
Not everyone. Hair that's uncolored, rarely heat-styled, and feels strong doesn't need repair. K-18 earns its spot for:
- Blondes and heavily lightened hair. Lightener is the biggest keratin-chain breaker in the building. Guests going brighter, like the work in our balayage vs foils guide, benefit most.
- Hair that stretches when wet or snaps when dry. Those are the classic signs of broken internal structure.
- Extension guests. Your natural hair carries the install, so it needs to be strong. Marie talks about hair health constantly with extension guests.
- Hair recovering from box color or a rough correction. Repair first, then color, in that order.
What K-18 won't do
It won't smooth frizz the way a Cezanne smoothing treatment does, it won't add tone like a gloss, and it won't undo a haircut's worth of split ends. Split ends get cut, full stop. What it does is make the hair you have stronger, which makes every other service work better.
How do you book it?
You can add a treatment to any color or cut appointment, or book it on its own. If you're not sure whether your hair needs repair, smoothing, or hydration, say that in your booking note and we'll assess in the chair. Everything we offer is on the service menu.
K-18 questions from the chair
Is K-18 the same as a deep conditioning mask?
No. Masks condition the outside of the hair and rinse away. K-18 is a leave-in peptide treatment that works inside the hair shaft, reconnecting broken keratin chains. Hair that needs softness wants a mask. Hair that feels weak or stretchy wants repair.
How fast does K-18 work?
It starts working in a single application, and the effect builds over the first several washes as you keep using it. Guests usually notice hair feels stronger and less stretchy within the first few uses.
Can I get K-18 with my color in the same appointment?
Yes, and that's the most common way we use it. It slots into a lightening or color service, so the repair happens right when the hair is being asked to do the most.
Do I use conditioner with the K-18 leave-in mask at home?
On K-18 wash days the routine changes: shampoo, skip conditioner, towel dry, apply the mask, and leave it in. Your stylist will walk you through it before you take one home.
Will K-18 fix my split ends?
No treatment fixes a split end. Once the hair has physically split, the fix is a trim. K-18 makes the rest of the strand stronger so new splits are less likely.
Is K-18 safe for fine hair?
Yes. It's a lightweight leave-in, not a heavy mask, so it doesn't drag fine hair down. Fine-haired guests who lighten are one of the groups we recommend it to most.
If your hair feels weak, stretchy, or fried, start with a treatment appointment and we'll rebuild from there.
Book a treatmentCurrent pricing lives on the service menu.