L'Oréal Serie Expert Metal Detox Metal Neutralizer Pre-treatment - 500ml L'Oréal Professionnel Metal Detox Metal Neutralizer Pre-Treatment is a pre-service treatment designed to neutralize metal particles inside the hair fiber before color, balayage, or lightening services. Metals within the hair fiber can increase the risk of breakage and interfere with color absorption, leading to uneven or less vibrant results. 87% less breakage risk. 100% reliable colour result. Colour is homogeneous, lasts longer and is intensely shiny. Use Spray on dry hair from tip to root in successive separations. Apply 8 to 10 pumps on short hair and 15 to 20 pumps on medium to long hair. Focus on lengths. Knead and comb through for optimal product distribution. Let it air dry for 3 to 5 minutes. Do the colour or bleach service as usual.