Insulin injections help bring down the amount of glucose released by the liver during the night, bringing morning blood sugars levels back to normal. Carbohydrates are broken down into glucose, which is the fuel that gives our bodies energy. Insulin's important job is to help glucose get into the body's cells. Insulin Helps Build Muscle When you've been sick or injured, or if you're recovering from surgery, insulin helps you heal by bringing amino acids (the building blocks of muscle protein) to your muscles.