Serie Expert Keratin Alpha Sleek Shampoo 500ml by L'Oréal Professionnel. Features: * Reprogram hair for up to 2 weeks of frizz control* * For up to 5X smoother hair with up to 2x less frizz** * Controls unwanted volume for daily styling in half the time*** * Progressive Reprogramming: After 4 uses, Smooth Transformer resets hair discipline**** at the Keratin Alpha level for a total fibre transformation***** *Consumer test on 68 participants, 1 application/week for 4 weeks. Based on a 15-day break observation **instrumental tests ***Instrumental tests with routine 4 times of Shampoo + Smooth Transformer + Leave-on ****After 4 applications of Smooth Transformer. *****Instrumental and consumer tests.