Baby Formula question

Gain is made by Abbott labs, the makers of Similac. I would call my ped and ask for sure, but maybe you could also call the Similac company and ask which formula is closest in composition to the Gain Advance. We brought one large can home from Guatemala (our dd was on the Nan 2) and we've had no problems switching her at 1/2 and 1/2. Our ped said at 7mo she shouldn't have any problems and basic formulas are so close in composition anyway. He had no preference in brands. Oh and WELCOME HOME! :)