IGF can cause some mild hygo side effects. If your goal is to make mass gains, I would continue to use carbs preworkout, or better yet, intra workout. I would take your IGF about 5 min before you train.
On the note of carbs, dextrose is about the bottom choice for intra workout. Highly branched cyclic dextrin is the best, followed by waxy maze. I would take your IGF before training and then sip on some HBCD along with 20g of EAA's through the workout.