Insulin Concentrations
The doctor always prescribes insulin dosage in units. Thus all types of insulin (crystalline, NPH, Lente, and so forth) is available in 10-ml vials that contain either 40 or 100 U/ml. U-100 insulin contains 100 units of insulin per ml. Doctor may also prescribe U-500 insulin for selected individuals.
The concentration of an insulin preparation is always clearly marked on the bottle. The caps on the vials may be color coded, and the vials may be shaped differently according to the concentration of insulin. You should read the label of insulin vial carefully.