Olaplex Blonde Enhancer Toning Shampoo No.4P is a highly concentrated purple shampoo which brightens your blonde and neutralizes brassiness after one use. It is formulated with Olaplex's patented bond building technology that is intensely hydrating and reparative. Olaplex have really cracked the code with this combo! This best-selling shampoo allows you to control the toning level. The longer you leave it in the brighter your results!
Scientifically Proven:
3x Brighter* *Compared to top purple shampoos - Source Olaplex
Bond-building repair is needed in all types of hair damage including:

Damage caused by heat from styling tools
Damage caused by Chemical factors such as colours, perms and chemical treatments
Damage caused by brushing and friction
Damage caused by environmental factors such as UV damage, humidity and hot/cold weather conditions.

The patented OLAPLEX Bond Building technology works on a molecular level. Bis-Aminopropyl Diglycol Dimaleate, a single molecule, dramatically improves the hair strength, protects from within, and provides immediate results for all hair types.