aahhahhahahahahahahahahahahhah ahahahahhaha!!!!!!! What is it about today that brings out these thoughtless posts! Let me give you some advise:
#1. Don't come here and post a question if you haven't even taken the initiative to research for yourself, a question like yours puts a bad taste in mine and many other guys mouths. The stupid thing is that in literally 10 minutes you could have learned everything you needed to about insulin, dosage, effects, risks, etc!!!!
#2. List your stats!!!! How can we help you if we don't know a thing about you. (Age, Height, Weight, Goals, AAS Experience, Special Health Problems)
#3. If you are below your genetic potential and you can't grow naturally, there is no amount of AAS or Insulin in this case that will help. It all comes down to DIET & WORKOUT, but in your case mostly DIET. If you can't get those 2 things in check, you will be wasting your time and money on these "supplements" (Notice they are called supplements, because they are meant to supplement an already stellar DIET & WORKOUT)
I know that I may have come off harshly but, you were probably just going to hear it from someone else anyway... I can however offer you some encouragement: When I started lifting seriously (Age 16) I weighed 110lbs @ 6' tall. Talk about gangly LOL!!! Well it's been slow going but once i got my diet in check (Basically forcefeeding myself a moderately healthy 4000 cals a day) I gained pretty steadily. Six years later I now weigh 181lbs at 7% BF, that equates to 71lbs or an average of about 12lbs/year. Thats only 1lb a month but if you can consistently gain weight you will eventually attain your goal. So the take home message of this is; Increase your caloric intake, and keep your eye on the prize. Once you've learned how your body grows ie: diet composition, workout schedule etc. then consider AAS or Insulin, if you wish.