Mommies beware! My husband and I have our ds on Similac and he had been having bad gas and fussiness. We talked about it with his ped. and she suggested trying the Similac sensitive. It helped with the gas slightly but I noticed that he was acting differently. His sleep pattern changed and he seemed to get really cranky about an hour after feeding. I also noticed that the formula itself would float on the top of the water instead of mixing right away and there were sooo many bubbles! I decided to take a look at the ingredients and noticed that the first ingredient was corn syrup and the third was sugar. Neither of these are listed in the non sensitive formula. We decided that we could deal with the gas over feeding him sugar. Just a warning for those that have babies with sensitive tummies. Might want to look into a brand other than Similac.