Insulin is an anabolic hormone, meaning it facilitates the building new tissue. Insulin has as well distinct anti catabolic properties, meaning it helps to maintain tissue under stress and high metabolic demands.
These traits makes it a valuable addition to the toolbox of many advanced bodybuilders. Insulin especially shines when combines with GH as they offer synergistic metabolic effects - The GH causes an increase in blood glucose levels, while the insulin helps to shuttle glucose back from the circulation to the tissues, hence when combined properly they balance each other and enables optimal metabolism
Insulin must be used in caution, and before using insulin it's advised to seek proper professional health care monitoring and consultation