How old are you? It's good that you got the bf down first along with nice size. Back looks good bro. I think after 4 years of serious training you can begin juicing, but I also think it's a bit of a shame to blast your receptors with so much right out of the gate. You can make great gains will lower dosages, with or without a combination of supps.
Where do you go from here in order to get to the next level? 2 grams? 3?