insulin is one of the most anabolic hormones in the human body, you could put on some muscle mass if you used insulin alone, but you would also gain a large quantity of fat.
i by no means am a biochem expert.....but insuling has a synergistic effect with growth hormone, T3, and an AAS, preferable testosterone
the growth is going to make the glycogen conversion from the insulin more efficient and the t3 is going to keep the metabolism burning hard enough that you wont gain that much adipose tissue from the insulin
so you can use it on your own, but unless you a very high metabolism i would be careful