Kerastase Re-Substance Fibro-reinforcing Gel for Mature Hair The first revitalizing filler service to densify and strengthen mature hair from within. The ritual: This revitalizing filler service combines Intra-Cylane, an innovation from la Recherche Avancee L’Oreal, with essential ingredients to reinforce mature hair. On contact with water, this filler instantly expands, acting as a framework for the hair fiber. The result: Mature hair is instantly strengthened from within, with added density and improved styling manageability.Each tube is 0.68 oz