LO has been on the regular similac advance since day one and has done really well on it. I have heard that the ingredients in costco's brand of formula are very comparable to the similac advance, and have been debating whether or not to try it. Price wise it is just so much cheaper, and I'm wondering if he will do just as well on that. Anyone try it yet? Or know anyone who has used it?                
                             
        
Re: Costco Formula
I did my research. The ingredients are the same, there are three that are in different amounts, but I didn't find much of a reasoning for it. Kirkland is made in the same factory as Similac.
So we switched and saw no difference.