This developer is for licensed hairstylists and colorists, not a retail consumer applying color at home on their own. It's meant to be mixed with a Matrix permanent hair color or lightener as part of a professional color service — typically when a client needs strong lift (up to about four levels) or coverage of resistant gray hair, rather than a subtle, low-volume gloss or deposit-only service. Anyone without professional color-mixing experience should not use this product on its own; it has no styling or conditioning function by itself.

The reason a salon reaches for this specific developer rather than a generic peroxide is consistency: Matrix formulates its cream developers to behave predictably alongside its own permanent color lines, at a fixed 1:1 ratio, so a colorist can move between 10, 20, 30, and 40 volume without the mixing behavior changing unpredictably. The 40-volume strength specifically exists for services that need real lift — several levels of lightening or coverage on hair that's resistant to lower-volume processing — rather than for routine, low-lift color work.

For professional use only. Combine Matrix Cream Peroxide 40 Volume with Matrix permanent hair color (or lightener, per that product's specific instructions) in a 1:1 ratio by volume in a non-metallic bowl, mixing until smooth and uniform.

• Perform a patch test and strand test before full application per standard salon protocol
• Apply to sectioned hair according to the chosen color formula
• Process at room temperature, typically 30-45 minutes, following the specific tint or lightener's timing guidance
• Rinse, then shampoo and condition once processing is complete
• Do not substitute a non-Matrix developer, as Matrix states this can cause unpredictable results

Pros:

• Delivers up to 4 levels of lift, enough for significant color changes or resistant gray coverage
• Creamy, controlled texture designed specifically to mix evenly with Matrix tints
• Standard 1:1 mixing ratio keeps formulation predictable for stylists moving between volumes

Cons:

• 40 volume is the strongest, harshest option in the line and carries more risk of hair and scalp stress if timing or ratio is off
• Only compatible with Matrix color products — Matrix advises against substituting other brands' developers
• Requires professional mixing knowledge; not usable as a finished product on its own