V.R.
Hi M.,
I highly recommend you do a bit of research on Soy Milk. I just recently took one of my girls that has a sensitive stomach off of it. My daughter is lactose so I had her on Similac Lactose Free but then I had all kinds of people tell me how great Soy milk is so I tried it. Well - I started reading about the Soy milk and I found a lot of articles talking about how it has a lot of progesterone and it's not good for babies. My daugher is now back on Similac Lactose Free. You should definitely research it a bit before you give it to your son. Make sure you're okay with it. Good Luck!