According to the dietitian from gerber, all their formula have the basic recipe. They use partially broken down whey protein and add probiotic or prebiotics. If I remember correctly, it's not suitable for babies with milk sensitivity or intolerance. I could be wrong.
We tried the soothe version because we wanted to see if L. reuteri would actually help but then we found out that my baby was milk and corn sensitive.
My baby is taking Alimentum RTF and I totally feel your pain. Look on the bright side, at least they are not on Neocate or Elecare. Those are pricey. My baby was on them for a few weeks.