My nails were soft and peeling so much that I could not grow them past my fingertips. I decided to try Nail Envy because it has been around so long and generally gets good reviews. I got Pink to Envy, which is a pink-tinted version of Nail Envy and part of OPI's Strength in Color collection because I wanted a teeny bit of color too.I followed instructions exactly for about a month, applying two coats every Sunday and a new coat everyday, then taking it all off at the end of the week and starting over. My nails got a little better, but they were still peeling and softer than I wanted. I noticed that my nails looked and felt nice when the product was on my nails, but they were almost as bad as they were before I used the product when it was not on my nails. I think Nail Envy just glued together any fragile layers my nails had instead of strengthening the actual nail itself. Pink to Envy, despite being tinted, does yellow a little. It didn't happen on every nail, but I noticed my ring fingers seemed more susceptible for some reason. I just removed the product when I noticed this and applied a fresh coat. I think it won't yellow your nails as long as you remove the product before the stain transfers.Anyway, I ended up buying a bottle of Nailtiques Formula 2 Plus Protein, which actually did harden my nails. And that happened in about 2-3 weeks. Now my nails are very strong and can grow easily past my fingertips. There has been zero yellowing too.The only positive thing I can say about this product is that Pink to Envy gives you a very pretty, clean, glassy look. But if I were you, I'd skip Nail Envy and go straight for Nailtiques.