The Subrina Professional CremeOxyd hair oxidizing lotion is a critical component when using hair dye or bleach. It is designed to work with the dye or bleach to initiate the chemical reaction that leads to the desired hair transformation. The strength of the oxidizer (usually measured in volumes) can affect the level of color deposited or lifted. Always follow the specific instructions for the dye or bleach product you are using to achieve the best results.