You know, mixing igf-1 and insulin isn't a bad idea now that you mention it. I'd drop my dose of humalog or humulin-r if I was adding igf-1 lr3 to it though. Like, if your regular dose of humalog was 10 iu, drop it to 5-6 iu and add in your normal igf-1 lr3 and see what happens.
Some say you don't want to have insulin present when taking GH though- hence waiting to eat for about 1/2 hr after injection. But, that's been debated a lot. I've taken slin and Gh together. Whether that hurt the Gh shot, I can't say.