Deep Cleansing Shampoo Ph-balanced shampoo to ensure a deep cleansing that removes any impurities and residues from styling or previous treatments. Prep Shampoo helps open the cuticle, preparing the hair for better absorption of the subsequent treatment or service. Ideal before applying colors, perms, straightening systems, bleaching, but also specific treatments that need to provide structure, nutrition, strength to the hair shaft. Use: Apply to wet hair, massage and rinse. Repeat if necessary.