Control Your Blood Sugar by Knowing the C-peptide Level of Your Body


The C-peptide level is measured by taking the blood or urine sample to find how much our body makes insulin. Beta cells of the pancreas, secrete a substance called C-peptide along with insulin. Both C-peptide and insulin are released in about equal amounts at the same time. And, C-peptide stays in the body for a longer time than insulin. Therefore, measuring the C-peptide level can determine the level of insulin present in your body, which helps in diabetes treatment. Insulin controls the blood sugar levels whereas C-peptide level does not affect blood sugar.


Why to consider C-peptide test?

C-peptide test can find out –

  • How much insulin your pancreas is making when you have type 1 diabetes. And then, the physician can decide how much insulin treatment should be given to treat type 1 diabetes
  • Whether a person has type 1 diabetes or type 2 diabetes
  • The difference between insulin that body makes and the insulin given by injecting into the body
  • The cause of your low blood sugar (hypoglycemia)
  • Insulin-producing tumor of the pancreas (insulinoma)
  • The correct time to start insulin in a patient with type 2 diabetes
  • How well your treatment is working if you have diabetes



Let us understand the results of a C-peptide test.

  • A normal C-peptide level is 0.5 to 2.0 nanograms per milliliter
  • If the C-peptide level is more than the normal value, it indicates your body is making more insulin than usual
  • If the C-peptide level is less than the normal value, it indicates your body is making little or no insulin


Reasons for high C-peptide level in the body:

  • Your body is insulin resistant or may have type 2 diabetes
  • You may have a tumor known as insulinoma
  • Kidney disease
  • Have taken an excess of a certain class of drugs (sulfonylureas) to treat diabetes


Reasons for low C-peptide level in the body:

  • You may have type 1 diabetes
  • You are on insulin injection and it is suppressing the release of insulin from your pancreas
  • Have a poorly functioning pancreas
  • You may have liver disease or have taken insulin therapy
  • You’ve had your pancreas removed

Before going for the C-peptide test, ask your doctor whether you need to fast or stop medication for diabetes. Because the timing of your most recent meal taken and medications can affect the C-peptide level.