Brand Comparison · Hair · 2026
Olaplex vs K18 — Bond-Building Showdown
Two cult bond-rebuilding brands. Olaplex pioneered the category; K18 has different chemistry and a stronger evidence base.
Verdict
K18 wins overall — for most users.
Glow's editorial team tested both brands across 12 weeks. Here's where each one wins.
Side by side
Olaplex vs K18 — compared.
| Dimension | Olaplex | K18 |
|---|---|---|
| Active chemistry | Olaplex Bis-aminopropyl diglycol dimaleate. Multi-step bond rebuilding. |
K18 ✓ K18 peptide molecule. Direct keratin-bond restoration. |
| Best treatment | Olaplex No.3 Hair Perfector. 10-minute mask, weekly use. |
K18 ✓ Leave-In Molecular Repair Mask. 4-minute leave-in, single-use. |
| Best maintenance | Olaplex ● No.4 and No.5 shampoo + conditioner. Daily-use protection. |
K18 ● Damage Shield Shampoo and Conditioner. Daily-use bond protection. |
| Evidence | Olaplex ● Multiple peer-reviewed studies. The original bond-builder. |
K18 ● Patented K18 peptide. Independent salon trials show comparable results. |
| Pricing | Olaplex ● $48 No.3 mask, $48 shampoo, $58 conditioner. Premium pricing. |
K18 ● $95 leave-in mask. Premium pricing for the cult product. |
✓ = wins this dimension · ● = tie
Pick Olaplex if
When Olaplex wins.
Established system, pre-styling weekly mask, full daily routine.
Pick K18 if
When K18 wins.
Single-use leave-in for damaged hair. Strong on chemically-treated hair.
Frequently asked
Common questions.
Can I use Olaplex and K18 together?
Yes. Some salons use Olaplex pre-color and K18 post-color for layered repair.
Which is better for chemically-damaged hair?
K18 has stronger one-application impact. Olaplex maintains over time.
Are these worth the price?
For chemically-treated or heat-damaged hair, yes. For healthy hair, basic conditioner is fine.
Where to buy in Australia?
Both at Adore Beauty, Mecca, Sephora, and salon-affiliated retailers.