Hair Masks & Treatments · Head-to-Head
Olaplex N°.3PLUS Hair Repair Pre-Shampoo Treatment vs. K18 Leave-In Molecular Repair Hair Mask
Pre-Shampoo Bond Care vs. Four-Minute Leave-In Repair: Which Treatment Fits Your Damage Routine?
Not sure which is right for your hair? Take our 2-minute quiz to get a personalized recommendation.
Compare the Top Picks
Prices appear only when a current Amazon catalog response is available.
| Product | Key detail | Price | Buy |
|---|---|---|---|
| Olaplex N°.3PLUS Hair Repair Pre-Shampoo Treatment | At-home bond-building treatment that reduces breakage and strengthens hair from within | See price on Amazon | Check Price on Amazon |
| K18 Leave-In Molecular Repair Hair Mask | 4-minute leave-in peptide mask that reverses damage at the molecular level — the only treatment that reconnects broken keratin chains in bleached, chemically processed, and heat-damaged hair | See price on Amazon | Check Price on Amazon |
Olaplex
Olaplex N°.3PLUS Hair Repair Pre-Shampoo Treatment
See price on Amazon
K18
K18 Leave-In Molecular Repair Hair Mask
See price on Amazon
Why K18 Leave-In Molecular Repair Hair Mask Wins
K18 wins for hair that feels severely compromised after bleaching, chemical processing, or frequent heat styling because its four-minute leave-in format is designed for intensive repair without adding another rinse-out step. Olaplex N°.3PLUS is the better fit for a repeatable pre-shampoo routine when breakage prevention and maintenance are the priority rather than a concentrated reset.
Our Full Verdict
Choose K18 when your hair feels notably weak, stretchy, or difficult to manage after chemical services and you want a fast, targeted treatment after shampooing. Choose Olaplex N°.3PLUS when you prefer a pre-shampoo bond-care step that can become part of a consistent maintenance routine. K18 is the stronger choice for acute damage; Olaplex is the more natural fit for ongoing repair-minded upkeep.
Reviewed by the SilkierStrands Editorial Team · · Prices subject to change. Amazon affiliate links - we earn a commission at no extra cost to you. · How we test