How should I prepare for an insulin C-peptide measurement?

You may be asked to stop eating and drinking for 8 hours before having this blood test.

• Insulin and some oral medicines used to treat type 2 diabetes can change the test results. Your doctor may ask you to stop these medicines before your blood test.
• Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done or what the results will mean.