A nail strengthener is a clear polish that is applied to soft, flimsy nails to harden them and prevent them from tearing. Using a nail strengthener will help restore keratin to the nails and increase their toughness and durability. Brittle nails will not benefit from a nail strengthener, and may actually be worsened because they already contain more keratin connecters than necessary. Most nail strengtheners resemble clear nail polish and are applied directly to the nails just like normal polish.
Most people use nail strengtheners, also called nail hardeners, in hopes of achieving stronger, healthier, better-looking nails. People with weak nails often have difficulty growing their nails as long as they would like. Painting on a nail hardener will not speed up nail growth, but it will protect the nails and make them strong enough to grow to greater lengths without tearing.
Nail strengtheners are necessary when nails are soft, weak, or pliable. If the tips of the nails can be bent, or if the nail beds are easily scratched, a nail hardener will probably be beneficial. These conditions occur when the keratin strands that compose the nail are not held together securely enough. A nail-strengthening product will restore the links that connect the keratin strands, which results in harder, more durable nails.
Many people assume that any nail breakage is the result of weak nails, and that a strengthener should be employed. Brittle nails, however, break frequently because their keratin is held together too tightly and the nails are too hard. Applying a nail hardener to nails that are already excessively hard will not solve their brittleness and will probably end up making it worse. This nail type needs moisturizing, not strengthening, and can be treated using hydrating oils or creams.
Generally, nail strengtheners are sold in normal nail polish bottles and look similar to a regular clear varnish. A thin layer should be painted directly onto clean, dry, natural nails a few times a week depending on the severity of damage or weakness. Nail strengthener should not be used as a top coat over normal nail lacquers or artificial nails because it needs to be in direct contact with the natural nail to serve its purpose. It is acceptable, however, to apply a coat of nail strengthener underneath another polish. Acetone-based nail polish removers should be avoided when using nail strengtheners because they can dehydrate nails and make them brittle.