Is it bad to switch formulas? Should you gradually introduce a new brand as the original brand is still being used? I have 3 different kinds I've received from doctors, mail samples, etc. I hate to waste it. So far, I'm breast feeding/pumping and given a few similac advanced bottles. My supply doesn't seem to be keeping up with her. So in addition to researching ways to remedy that, I thought I'd also consider I just may have to move her to formula eventually.
Re: Changing formula.