Olaplex LashBond Building Serum is a clear, lightweight lash serum that delivers highly effective concentrations of OLAPLEX Peptide Complex Technology, OLAPLEX Bond Building Technology, hydrating Hyaluronic Acid, and Biotin to the lash line to support and sustain the natural growth cycle and lash retention. Experience more conditioned, healthier-looking lashes In as little as 2 weeks and see the look of longer, fuller lashes in as little as 4 weeks. Get ready to see your full lash potential.