Hello Doctor, My Baby boy is 1 month 22 days old. His birth weight was 3.1Kgs, but thereafter it reduced to 2.80 kg in next 10-12 days and after 1 month he was 3 Kgs. When we consulted our local Pediatrician , earlier he said theres nothing to worry, but after 1 month since he was only 3 Kg.. he suggested us to take Nan or Lactogen 1. At that point of time i was not aware about the difference in those two formulas. Now after 1st week of Lactogen (30ml, 3 times a day) he was weighing 3.2 kg. And now for last 2 weeks we are giving him 45ml, 4 times a day. He is passing stool only after 4-5 days, but he pee s atleast 10 times a day. Should i switch to Nan, as it is easily digestible..or should i continue with Lactogen 1.