I have always had weak nails. They break, peel and bend, making it really difficult to grow them out to be the same length! If you have this problem too, I suggest trying OPI's Nail Envy Nail Strengtheners. Mine is the Matte version, for all the types of OPI Nail Strengthener go here: http://search.ulta.com/cosmetics/Opi%20Nail%20Envy They are $17 at Ulta, and I know that is really pricy (it was only $13 when I bought it, years ago) but it works wonders. (If you need to justify the price, just think "this is the same price-or cheaper-than a shirt) Like I said, mine is probably more than 4 or 5 years old, and it still works!
The photo above is my new bottle of OPI Nail Envy, not the one that is 4 or 5 years old.
I like to use two coats of this after I take off my nail polish & before redoing my nails. Painting your nails constantly can make them weak, so I like to use this in between manicures. This can also act as a base coat for nail polish.
Nail Polishes Swatches