L'Oréal Professionnel Serié Expert Metal Detox Metal Neutralizer Pre-Treatment Spray for Hair Protection During Colour Services 500 ml/16.91 oz

Tap water carries trace metals, copper mostly, and hair collects them. You cannot see it happening and it makes no difference day to day, but the moment you put bleach or colour on that hair the metal reacts, and the result is breakage, dullness, and colour that lands somewhere other than the swatch predicted.

Metal Detox is the pre-treatment L'Oréal Professionnel built to deal with it. You spray it on before the technical service, not after.

• Neutralises copper and other metal deposits sitting in the fibre
• Makes colour and lightening results more predictable
• Reduces the breakage that follows a technical service on metal-loaded hair
• 500 ml, which is a salon backbar size rather than a home one

Worth knowing that it belongs to colour work rather than to a general care routine. If you are not colouring or lightening, it has nothing to do.

Hard water areas make the difference most visible. The copper load in hair is higher there, so the case for neutralising before every lightening service is stronger. Follow the timings printed on the bottle rather than guessing, since this is a backbar product written for salon use.