This 3ml lash and brow serum is a one stop shop for thickening and growing lashes and brows. From the hair experts at Actiiv Hair Science. Amplify Lash and Brow Serum promotes the appearance of thicker, longer lashes and brows. Utilizing clean ingredients and a proprietary amino acid complex and peptides, this innovative serum encourages a stronger lash and brow structure which leads to longer, thicker looking lashes and brows. Formulated with natural ingredients, this serum is safe to use on even the most sensitive of skin. 3 ml is a 3-4 month supply on average. 5 ml is a 5-6 month supply on average.