My wife ran out of milk when our son was just 2 or 3 months, it was pretty tough period for our family. I was actually confused how I was supposed to act and what to say, but I was as nervous and worried as she was. We immediately went to a pediatrician and he advised us some formulas to try. It actually depends on your baby and his nutrition needs, you know, you can't just give him/her what you firstly bought and feel safe and calm. We have had many sleepless nights when our son was feeling not so good because of the formulas. Thus, you just need to ask for advice the doctor, from my side I can suggest to try only hipp formula of organic baby food and see if it suits your baby. It's the best variant by far we could've found.