You want to use only .6% AA for IGF. No bac water. You don't need to inject into a specific muscle. Just use whatever is easiest for you. IGF is systemic, meaning that once you have injected it into a muscle, it is carried away and into the blood stream. When IGF first became popular, there was talk of it having a local effect. Since then, that idea has been widely abandoned. I've used it every way you can, bi-lateral, in the muscle trained, IM in a single muscle, sub q, IM in the same muscle every time for 8 wks. I have seen no difference. I would just take it IM, in whatever muscle is most easy and comfortable to do