Normal insulin levels for non-diabetics are usually between 60 and 100 mg/dl and may rise to 140 mg/dl after eating, reports the University of California. Diabetics may have insulin levels that range from as low as 25 mlU/L at fasting to as high as 30-230 mlU/L after recent glucose administration, reports Medscape.
Insulin levels are measured by doctors to make sure that the patient's body is producing the proper amount. Insulin works to help the cells and tissues in the body maintain appropriate blood glucose levels. Diabetics have insulin resistance and their bodies are not capable of using insulin properly, reports the U.S. Department of Health and Human Services.