Which product is used to strengthen and protect natural nails?

Nail hardener is specifically formulated to strengthen and protect natural nails. It contains ingredients that help to reinforce the structure of the nail, making it less prone to breaking or chipping. This type of product is typically applied directly to the nails and can provide a protective layer, thus enhancing the overall durability of the nail while also promoting healthy growth.

Other products listed serve different purposes. Nail polish remover is used to remove existing nail polish and does not have any strengthening properties. Moisturizing cream can hydrate the skin and surrounding areas but does not specifically target the nail structure itself. Cuticle oil is designed to nourish the cuticles and surrounding skin, promoting overall nail health but does not actually strengthen the nails like a hardener does. Each of these products has its own beneficial role in nail care, but when it comes to strengthening and protecting the natural nail, nail hardener is the most appropriate choice.