I've tried every single insulin protocol there is over that last 10 years.
The easiest one to follow and the one that does not require any diet adjustment is taking a few small doses per day of regular insulin, 2-4 iu at a time.
Very safe, 0 chance of going hypo even without eating. No fat gain from the insulin since you are not eating extra. Reduces the amount of insulin your own pancreas has to make - reduces stress on pancreas.
Benefits: fuller muscles from same amount of food, synergy when taking with gh.
I've watched/listened to all of collete nelsons and dave palumbos info on insulin and metformin and made a conclusion that metformin is not a good drug for bodybuilders and low dose insulin is the way to go, mainly for the health benefits when using hgh. Is taking metformin detrimental? probably not, but the side effects outweigh the benefit in bodybuilding terms I think