Hair repair is a science, not a secret. Gliss Hair Repair System with Keratin Serum gives you the power to achieve beautiful, healthier-looking hair! It combines hair identical keratin and a powerful cell-shield for a two-fold action. It repairs existing damage and prevents future damage by fortifying the cell structure and fighting free radicals. Our best repair ever: prevents damage before it happens, for long-lasting beautiful hair. Available in more than 50 countries, and has been trusted by millions for over 60 years.