I want to stick with Pro-Advanced Similac but I got a container of organic Similac as a gift and I also got 3 little containers of pro-advanced, pro-comfort, and another one I forgot the kind they’re all Similac though. I don’t wanna waste the free samples or the Organic one can I switch off from them or will it cause my baby stomach problems? // since the biggest container I have is the organic one I want to keep on continue just buying that one if it doesn’t upset baby and I will find someone (friends/family) to take the little containers of the advance and what not