Fantastic formula When I was weaning my son off of breastmilk we slowly switched over to Similac. At first I was very worried that he may have an upset belly, however, the Similac caused no issues for him and the transitioning went fantastic. We usually purchase our Similac with Iron at Walmart in the premade quart as it is the cheapest place we have found so far that sells it. It has kept his weight up which is a huge plus for us as he is a little guy. It is very easy to open and doesn't take up a lot of room in our refrigerator.