Obagi Nu-Cil Eyelash Enhancing Serum boosts the appearance for fuller, healthier looking lashes. Natural lashes can change over time. Stress level, hormones or aging may cause decrease in volume and density. Nu-Cil can help with the process to better looking lashes. Key Ingredients: NouriPlex Technology, Benzoate, Biotin, Panthenol, Sodium Hyaluronate, Phenoxyethanol. How to Use: Cleanse the skin, apply a thin layer of Obagi Nu-Cil Eyelash Enhancing Serum to the base of your upper lash line. (Do not apply to your lower lid or other areas). Wait 90 seconds for serum to dry entirely prior to applying other product to the skin. For external use only.