Pro Longer shampoo for long hair helps to thicken the appearance of your long hair whilst making it visibly healthier and stronger looking.​ When used with the Pro Longer conditioner for long hair, there is a hair breakage reduction*.​ The Filler A-100 technology used is patented to L'Oréal Professionnel, and it works by penetrating the fiber core to plump and thicken the hair from the inside.