I have very long nail and i always used the VITRY nailcare, wich was very very effective. I was shopping at Winners and i saw the ORIGINAL NAIL SYRENGTHENER by OPI and i decided to try this product because i loved their nailpolish. What a mistake..... i did not broke a nail since 6 or 7 months with the aVitry polish, and the second week i apply the OPI, i broked 2 of my nails. They started to became yellow and thin. I am very disappointed by this product. I did not recommended it at all!!!!!!!! It took me 2 months to repair the use of 2 weeks of this product. I am seriously sad and angry because they were so beautiful before i use this product... use Vitry, not OPI!!!!!