Ok, I didn't read through all the replies, so if I am repeating somebody else, my apologies. I think he took the formula only for the simple fact that him and Peter never resolved their conflict. Peter actually just dismisses all of his obsession in favor of saving MJ, I'm sure that rubbed him the wrong way. So I think is already implied that with the discovery of his fathers equipment and juice, that Harry would impliment it. But then again, I could be completlely wrong.