The Lendan Next Liss Age Smooth Enhancer ampoule, with kera-cysteine concentrate and 18-MEA, enhances the straightening effect so you can enjoy up to ten weeks of healthy, shiny, nourished and, of course, straight hair. Formaldehyde-free PROCEEDS: With 18-MEA and hydrolyzed keratin. HOW TO USE:<,strong> Mix with step 2 Active Serum (40 gr of Active Serum + 1 Booster Ampoule).