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.