Nail hardener being applied

Perfect polish doesn't last long when your nails split, chip and peel easily. Repeated water exposure, which can be exacerbated by low humidity, can result in dry and brittle nails, as can genetics. Nail hardeners work to strengthen your nail plates, making them less likely to split and break.

Before you apply this strengthening product, you have to choose between the two types of nail hardeners. Reinforcing nail hardeners serve as a top layer for your nails, strengthening their natural structure. Ingredients such as nylon and sulfhydryl protein create a smoother and stronger nail surface.

Cross-linking nail hardeners strengthen finger nails by connecting their protein chains through chemical bonds. This makes them stronger and the surface of the nail harder. The only downside is that they're sometimes so effective that they might make your nail too hard, less pliable, and more prone to breakage.


Applying a nail hardener is straightforward. If you've applied nail polish, you're equipped to apply a nail hardener.

Clean your nails, removing any polish and washing and drying your hands thoroughly.

Brush a thin layer of hardener onto your nails in three strokes: one down the center and two along the sides of the nail.

Allow the nail hardener to thoroughly dry. Polish over the nail hardener with your favorite shade, or go natural.


If your nails are dry, brittle and damaged, repeat these steps daily or every other day for seven to 14 days. Repairing damaged nails does not occur with just one application of nail hardener and instead requires consistent use. Once your nails are stronger, shift to a once-a-week application for upkeep.

Nail hardeners use formalin and methylene glycol as the primary strengthening ingredients. Formaldehyde is another commonly used ingredient in these products_._ As a result, concerns about the safety of of nail hardeners exist.

However, the U.S. Food and Drug Administration has approved formaldehyde and formalin for use in nail hardeners, as long as the concentration of the ingredient is no more than 0.2 percent of the total weight. Thanks to these low levels of the ingredients, as well as the limited inhalation exposure and quick drying times of nail hardeners, the products are deemed safe to use.