 of formula from many name brands.  Unfortunately he had adverse reactions to everything we tried, including soy products.  We finally tried Organic Similac.  This was by far the most expensive, so we started with the powder.  This stayed down & he didn't have any reactions (rashes, hives, throwing up, etc).  After a couple of months he began spitting up a little powdery substance (guess we didn't mix well enough).  We then tried the Premixed Similac Organic.  Voila!  Perfect.  No adverse reacti