Made for colour-treated hair, applied after any chemical service such as permanent, demi-permanent or toner work. The 1 L pump bottle is the salon size, so it suits stylists using it at the basin after every colour, and clients who colour often and want the same step at home between visits.

It is a professional Oligo Professionnel product sold through salons and professional beauty retailers.

The point of Colour Lock is the pH. After a colour service the cuticle is left open, and a 4.0 pH treatment helps bring it back down and seal it, so the colour you paid for stays brighter for longer and the hair feels smoother. Many conditioners claim to be colour-safe; this one is designed specifically as the closing step of the colour service itself.

Use after any chemical service. Apply to the hair and distribute thoroughly, leave on for 5 minutes, then rinse.

Pros:

• Low pH of 4.0 is aimed at closing the cuticle after colour, which is the step that helps colour last
• Only five minutes on the hair before rinsing
• Vegan and sulfate-free, so it fits a colour-safe routine
• Litre size is economical for frequent use

Cons:

• Only sold in the 32 oz (1 L) size in our store, which is a lot of product for occasional use
• A rinse-out step, not a leave-in, so it adds no heat protection
• Oligo has not published a full ingredient list