I really like the Pca line and notice the difference within days of using their serums specially with the size of my pores. The only problem is that you have to continue using them and it can get expensive (even though a little goes a long way the serums usually last me months). As soon as I stop using the serums my acne comes back my pores look larger etc...but they work and they work great while you use them specially when you combine them with some of their other products.