Each day, nails are stripped of natural oils (lipids) supplied by the cuticles. Lipids move through the porous structure of nails to provide flexibility which helps reduce breakage. Water, soap, detergents, nail polish removers, and shampoo, dramatically diminish lipids. At night, while the body is at rest, is the perfect time to restore these lipids. Barielle Intensive Nail Renewal Oil replicates the body's natural lipids and miraculously penetrates nail polish (without damaging manicures) to restore flexibility. Flexible nails resist breaking, resulting in the long nails you want.