A nail hardener is brushed onto your nails to make them stronger than they would be without an external product. There are plenty of reasons why nails need to be strengthened with a nail hardener, be it age, nutrition, genetic factors, or for people who use their hands water often. Hardeners should be applied before a manicure or as part of a weekly, or bi-weekly routine for nail health.
Some hardeners are made to provide a protective barrier from the elements. They don’t penetrate the nail or work to provide any sort of nourishment to them, but rather coat your nail to prevent moisture from seeping in, while also making the nail structurally stronger — to prevent breakage. These products are also great for a base coat before applying nail polish.
Other hardeners are formulated to actually change and strengthen the nail from the inside by penetrating the surface and increasing the keratin levels in the nail itself. This type of hardener normally uses formaldehyde as a penetrative ingredient, and contains calcium to further strengthen the nail.
Most nail hardener products come in the same form as nail polish, and are brushed on. Hardeners that create a barrier between your nail and the elements can be used as frequently as you wish. Penetrating hardeners need to be used sparingly. They are extremely effective, but over-use can actually cause your nails to become weaker, by cracking. Try to avoid putting any hardener on your cuticles or any other area where skin is, regardless of the type of hardener you’re using.
Aside from a quality nail hardener: Make sure to use care when manicuring your nails. See-sawing with your emery board or file is a no-no. This is one of the hardest rules for most people to follow, as filing in one direction only does take slightly longer and requires a tad more concentration. Keep the tips of your nails smooth, to prevent them catching on clothing and breaking.