Colourists and salons doing permanent colour, balayage, highlights or bleach, particularly on clients whose hair has been exposed to hard or copper-rich water, or who have had breakage or unpredictable results before.

It is a professional pre-service product, sold for in-salon use. It works on all hair types and with any colour or lightening brand.

Metal in the hair is one of the hidden reasons a colour comes out off-tone or a lightening service causes breakage, because the metal reacts with the oxidative chemistry. This spray deals with it before the service starts: its 10% Glicoamine concentration neutralizes metal inside the fibre, so the colour or bleach can work on cleaner hair. L'Oréal says lift isn't affected and colour uptake is optimized, and paired with the Metal Detox shampoo and mask afterwards it gives clients a full protocol from chair to home.

• On dry hair, spray from tips to roots, section by section.
• Use 8 to 10 pumps on short hair and 15 to 20 pumps on medium to long hair, focusing on the lengths.
• Knead and comb through to distribute.
• Let it air-dry for 3 to 5 minutes. Do not rinse.
• Carry out the colour or lightening service as usual, then cleanse with Metal Detox Anti-Metal Cleansing Cream Shampoo.

Pros

• No rinse and no change to the colour or lightening protocol
• L'Oréal reports no impact on lift, so lightening times stay the same
• Works with any colour or bleach brand
• Fragrance-free ingredient list

Cons

• Needs 3 to 5 minutes to air-dry before the service, which adds a little chair time
• The 87% figure comes from the full protocol including shampoo and mask, not the spray alone
• Professional use only, not an at-home styling product