Quick Reference
- Full form
- C-Peptide (Fasting)
- Sample type
- Blood
- Fasting
- 8 to 10 hours required
- Marker measured
- 1
- Report turnaround
- Same day
- Available at
- All locations
About C-Peptide (Fasting)
C-Peptide helps your doctor understand how much insulin your own pancreas is producing, which is especially useful for distinguishing between types of diabetes or assessing pancreatic function.
We ask for 8 to 10 hours of fasting before this test, since food intake directly affects insulin and C-Peptide levels. Results are available the same day.
How to Prepare
- Fasting for 8 to 10 hours is required before this test.
- Water is fine during your fasting window.
Frequently Asked Questions
Why is fasting required for a C-Peptide test?
Food intake directly affects insulin and C-Peptide levels, so fasting gives an accurate baseline reading.
How long should I fast before this test?
We recommend 8 to 10 hours of fasting beforehand.
What does C-Peptide testing help diagnose?
It helps distinguish between types of diabetes and assesses how well your pancreas is producing insulin.
Is this test done alongside blood sugar testing?
It is often paired with glucose testing for a fuller picture of your insulin and blood sugar status.
How soon will my report be ready?
Same day.
Is home sample collection available?
Yes, ideal for an early morning fasting sample, in all City Care Lab service areas.
This page provides general health information and is not a substitute for medical advice. Speak with your doctor about your specific results and treatment.