If you saw my other review of OPI's Nail Envy (pink) you'll know that I'm fast becoming a fan of these nail treatments! As a whole the Nail Envy Original Nail Strengthener offers all the same qualities as the Nail Envy Pink, only it is to be used as a base coat under other nail colours whereas the pink alternative is a nail colour in itself. So if youre a nail colour enthusiast and are forever damaging your nails with acetone and polish but cant face to say goodbye to your malibu blue mani's this ones probably for you! Just like most nail treatments Nail Envy follows a course of two weeks, applying layers and removing layers on selected days, leaving you with lovely strong nails at the end of the cycle. The only downsides to this product are the price (£18) which correct me if I'm wrong is one of the 5 most expensive nail polishes on the market (up there with YSL + TF) and the fact that it does run out quite quickly because of the meticulous application, lets just hope I don't go getting too addicted eh?