I have struggled with weak, thin nails my entire life. Add damage from removing glitter polish, and it was a disaster! This final damage made my nails break and split so often they looked pitiful. That sent me looking for help and I found Orly's Nailtrition. I followed the instructions exactly, and after 3.5 mos, my nails are really strong and growing faster. I've tried a lot of things in my 63 yrs, and this stuff is impressive!!! My worst nail that has split for ages has stopped splitting! It wasn't overnight, but 3.5 months goes fast for me now. All my nails have grown above the tips of my fingers now! The only time they had ever been that way before was when I had acrylics! So I'm thrilled with Nailtrition! There is a noticeable ridge up, from thin to thick, when compared to my new nail growth, and even my badly damaged thin nails have strength and flexibility! I bet the new growth is going to turn out even stronger! Along with using a Czech glass nail file, and NO clippers, I'm now giving my hands and nails the royal treatment daily: frequent daily moisturizing, gloves to protect, keeping nails polished (makes them strongerwhen they're polished), and of course, frequent use of Orly Nailtrition. I only used it without any polish, one week on, one off, when my nails were super nubs....probably the first 4-6 weeks. Now I'll put 2 coats on plus Orly Defender, as a base coat. Then do my mani. The results are so impressive that I'll never be without it again!