C-peptide
Shows how much insulin your own pancreas is producing - useful when the type or cause of high blood sugar isn’t clear.
TypeBlood test
HowStandard blood draw, often fasting.
How oftenWhen advised.
BeforeFollow the lab’s fasting instructions.
WhoPeople with diabetes where the type is unclear, or unexplained low blood sugar.
How much insulin your own body still makes
Injected insulin and your own insulin look the same in blood. C-peptide is made only when your pancreas produces insulin - so it shows how much your body is making by itself.
Type 1
“Is my pancreas still producing?”
Levels fall as insulin-making cells are lost.
Often low
Type 2
“Is my body overworking?”
Early on, levels are often high as the pancreas works harder.
Often high
Unclear type
“Which type do I have?”
Helps guide treatment when the diagnosis isn’t clear.
Clarify
Is it right for you?
Worth considering if…
- You’ve been diagnosed with diabetes and the type is unclear.
- You have unexplained episodes of low blood sugar.
A better option if…
- You want to screen for insulin resistance - fasting insulin is more commonly used.
How it’s measured
Lab blood draw
Sometimes measured alongside glucose.
The full picture
What is it?
A by-product released when your pancreas makes insulin.
What type of test is it?
A blood biomarker.
What does it measure?
C-peptide concentration - a stand-in for your own insulin production.
Why might someone consider it?
To tell type 1 and type 2 diabetes apart or investigate low sugars.
Who is it most relevant for?
People with diabetes or unexplained hypoglycemia.
How is it performed?
A blood draw.
How often might it be considered?
Only when needed.
What can the result help you understand?
How much insulin your body is making.
What are its limitations?
Affected by kidney function and timing.
What should it be viewed with?
Glucose, HbA1c and diabetes antibodies.
Where to get it
Through your provider
Usually ordered when symptoms or results point to it.
Lab services
e.g. Quest Diagnostics, Labcorp - typically with a provider order.
Specialists
Your provider may refer you to a specialist to interpret it.
Names are examples only, not endorsements. Your provider can often order the same test - and help interpret it.
Connected to
Questions to ask your provider
- Would C-peptide help clarify my diagnosis?
Ziva Health
One test is a snapshot. Ziva shows the whole story.
Ziva brings your lab results, wearables and daily readings together - and Isabella tells you what’s changing and what to ask your provider next.
Refer Ziva to my provider / care team
Is your provider not on Ziva yet? Send them a link in under a minute - once they join, they’ll see your C-peptide result alongside your other trends and get alerts directly.
Refer my providerAlready seeing your provider?
Bring your Ziva 30-day report to your next appointment - your C-peptide result and daily trends in one view, so the conversation starts with the full picture.
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Being listed doesn’t mean everyone needs this test. Educational only — not medical advice. Results should be interpreted with a qualified clinician. ← Back to Know What to Test