Hi, My Baby Is 2 Months Old. I Do Not

Hi,
My baby is 2 months old. I do not have sufficient breast milk supply. So I was giving her lactogen along with some brestfeeding. But from last 7 days I had started her giving cow milk.
Now I noticed that baby is doing potty 7 to 8 times but while giving lactogen she was doing potty 1 to 2 times.
I also noticed that she is not gaining weight as compare to when having lactogen.
Please suggest should I again start lactogen or continue cow milk??