Lancome Cils Booster Lash Revitalizing Serum 4ml a fortifying eyelash serum that conditions damaged and over-processed lashes from root to tip and reduces lash loss during makeup removal. This lash serum, infused with amino acids, revitalizes lashes including those damaged by daily makeup application, eyelash curlers, false lashes, and lash extensions. Applied twice daily, our lightweight, lash-loving formula refuels and cares for lashes day and night.