Of course it works. I do it all of the time. My dick is 25 inches long and 18 inches around. I need an 8 inch needle just to inject the shit into me now. I throw some injectable Winny into it too. Helps with the vascularity and veins.
Don't know bout synthol but curious about igf and I have read pgcl will increase size anyone tried pgcl for this..just can't bring myself to jab my cock I'm not hurting for size like that but having a 12 inch hog would be well worth just the expressions you would get from chicks when you whipped that hog out..(like holy sh*t that things gonna destroy me) ha ha