How do fingernails grow?

Your fingernails are composed of laminated protein layers of keratin. Nail growth starts out from the area at the base of the nail and under your cuticle. New cells grow and compact up against the older cells. They become hard (compacted) and are eventually actually pushed out toward the end of your fingertips.

This is why you usually have to wait months to see significant changes to your nails. You can more easily effect the "new" nail growth under the cuticle. This new nail will take time to grow out. Keep looking after this area under the cuticle and your nails should stay healthy looking.