K18 Hair
Up to 1.5% Cashback
New K18 Hair Customer
1.5%
Existing K18 Hair Customer
0.5%
Cashback timeline
Purchase
Tracked in
2 days
Confirmed in
90 days
Terms and exclusions
Refunds, cancellations and no-shows
Any rejected, cancelled, refunded, exchanged or returned purchases will not be eligible for Cashback.
Tracking disclaimers
- Your Cashback may be tracked at a different rate initially and adjusted to the correct rate when we confirm the transaction details.
Other terms and conditions
Never miss Cashback on K18 Hair
Get instant alerts on Cashback when you shop online with the ShopBack extension.
Cashback tips
Check carefully for Cashback exclusions and caps before you buy or book to avoid disappointment. Don't forget the terms and conditions on any promotion and campaign pages.
Complete your shopping in one go: Always start from this platform to visit the store directly, for every new transaction. If your store visit is interrupted by an app update or download screen, restart your shopping from our platform.
Don't click on any third party links or extensions or use VPN or adblocking software, as they could result in your Cashback not being tracked. Some examples include: Facebook ads, Google Ads, other loyalty or cashback extension links.
For K18 Hair, you need to clear your cart, close the K18 Hair app, open this platform to visit the K18 Hair app or website and complete your purchase there in order to earn Cashback. You need to do this for each purchase.
If you encounter payment errors during your purchase, you should restart your visit to the K18 Hair from this platform to ensure that your Cashback continues to be tracked.
K18 Hair can only confirm to us that a transaction is recorded if you accept all cookies that appear on their pages.
Shop and earn at similar stores
K18 on ShopBack
What is K18?
K18 is a US-founded biotech hair care brand whose flagship Leave-In Molecular Repair Hair Mask uses the K18Peptide, claimed to repair broken keratin chains, so pick your product, then check out through ShopBack before you pay, where ShopBack Cashback works like a discount, only easier than a promo code. Competes with Olaplex, Living Proof, Redken Acidic Bonding Concentrate, and Kerastase Genesis.
K18 vs Olaplex?
K18 uses a bioactive peptide leave-in mask with a 4-minute application. Olaplex uses bond-building chemistry across multiple products (No.0 to No.9). For a single-product routine, K18 wins. For a multi-step coverage, Olaplex has broader product depth. See our K18 vs Olaplex breakdown.
How often should I use K18?
Once every 4 to 6 washes for maintenance on healthy hair; once per wash for the first 4 to 6 uses on heavily damaged hair. Overuse does not accelerate repair.
Does K18 really work?
K18 has published third-party test data on the K18Peptide. User outcomes trend positive for restoring softness on chemically treated hair. Individual results vary by hair type and damage severity.
K18 refill vs full-size value?
Full-size (50 ml) typically offers the lowest per-mL cost. Mini (5 ml) or travel (15 ml) size makes sense for first-time trial.
K18 student and salon discount?
K18 typically offers ~15% off via Student Beans or UNiDAYS and a licensed hair professional discount. Newsletter signup ~10% first order. Subscription ~15% recurring.
Where to buy K18 cheapest?
K18 direct offers subscription discount. Sephora Beauty Insider and Ulta Ultamate Rewards members earn points and can use sale codes.
How do I earn ShopBack Cashback on K18?
Start at shopback.com/k18-hair. K18 orders are placed at k18hair.com. Go through ShopBack before you pay and the Cashback tracks to your ShopBack account.
How does ShopBack Cashback work with a K18 subscription discount?
Shopping K18? Pick your product, then check out through ShopBack K18 before you pay: ShopBack Cashback works like a discount, only easier than a promo code. K18 offers its own subscription discount and a newsletter code. The current Cashback is shown on the K18 page on ShopBack before you buy.
Last updated: 19 Oct 2026
