There are several different types of insulin each of the different types are made to work differently, because each diabetic is different in the way the body requires insulin. There is rapid acting insulin, short acting insulin, intermediate acting insulin, long-acting insulin and  pre-mixed insulin.

After testing the physician the right type of insulin will be prescribed for the way the body requires it to keep the blood sugar level in the normal range. There other factors that will decide how while the insulin to maintain the blood glucose level and this can include things like types of foods that are eaten, how often the blood sugar level is checked, age and the amount of exercise.