My month old daughter has had a time with formula. First we were on Enfamil Gentlease. This gave her so many tummy problems that we thought she was colic. The ped said switch to Soy or Similac Total Comfort. We switched to Enfamil Prosobee. This constipated her, but she thrived. She was a much happier baby than before. Then the ped said switch to Enfamil Reguline or the Total Comfort. Again, we went with Enfamil and she cried every time she was awake. I had this feeling that she had a milk protein intolerance, even if she doesn't- her system is extremely sensitive. So against my ped's advice, my mama bought a can of Nutramigen for us to start. I'm done with all the switching and wasting money and time on things that don't work. Sure enough, a few bottles in and my baby is much happier and calmer. I should have listened to my instincts earlier. I'm not sure if the dr was trying to save us money or what, but $40 is worth my sanity and my baby being happy!!!