Olaplex vs K18 — what we actually use, and when

Both Olaplex and K18 are bond builders — they reconnect the protein chains inside your hair that get broken when you lift, colour, or chemically treat it. They're not conditioners; they're structural repair.

Olaplex

Works on the disulfide bonds. Original formula (No.1, No.2 in salon; No.3 at home). Best applied during a colour service, mixed into the lightener so the bonds are protected as they break. Think of it as a seatbelt during the lift.

K18

Works on the polypeptide chains — finer, more recent science. Single application after washing, leaves on for four minutes, no rinse. Brilliant for everyday use between appointments and for repairing existing damage from heat, hard water, or old chemical history.

So which one?

In the studio: Olaplex during the colour, K18 after rinsing as a finishing repair. At home: K18 every 5-7 washes is the simple recommendation. If your hair is heavily compromised — extensions, repeat box dye, beach hair — Olaplex No.3 once a week is great too.