C-Peptide Test
Metabolic Health
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C-Peptide Test Levels

Being diagnosed with diabetes is not just about managing the symptoms of the condition. It is a lot more than that. There are so many unseen aspects that people who are not living with it are not even aware of. Even the way with which this condition emerges is a lot more nuanced than one can think of. The multiple tests, the uncertainty of the condition, the difference in the ways the symptoms may present themselves, etc, are just some of the aspects that occur and are taken into consideration. 

There are a few symptoms and warning signs that one can look out for. However, they can be masked under several different circumstances which is why people do not pay much heed to them in the initial stages. However, once the diagnosis is suspected, there are a plethora of blood tests, imagining, urine analyses, etc that need to be conducted regularly. 

Importance of C-Peptide Test

Among the plethora of tests, the most important ones would be the diagnostic ones. The C peptide test uses can help with exactly that. The reason why this test is considered important is based on what information it provides to the beneficiaries. Essentially, a C peptide test can help the doctors and the patients discriminate between the presence of Type 1 or Type 2 diabetes. How does it help to get this information? The c-peptide test helps one understand how much insulin is being produced in one’s body. The different levels of c peptide can give information of various kinds that will help attain this information. Also know about sugar in urine test.

What is a C-Peptide Test?

To understand c peptide levels in type 1 diabetes and what it entails, it would primarily be important to gain an insight into what c peptide is. When we speak about diabetes, the first hormone that comes to mind is insulin. This is the hormone that plays a key role that can cause the symptoms of this condition. The main function of insulin is to bind to the glucose molecules in the body, cells, and tissues. The islet cells of the pancreas produce insulin. However, that is not the only hormone they produce. 

The beta cells in the pancreas initially produce a protein – proinsulin. This proinsulin is then broken down into one molecule of insulin and one molecule of c peptide. In other words, there is an equal number of insulin and c peptide that is released into the body at any given time. However, these are not broken down in the body in the same manner. Insulin is broken down at a variable rate by the liver. The kidneys, in turn, work to break down the c peptide molecules at an almost steady rate making c peptide a much more reliable manner to measure the level of insulin in the body and the overall function of the beta cells of the pancreas.

What is the Use of the C-Peptide Test?

The vitality of the c peptide level normal range cannot be overstated. This range is what will finally give an insight into the type and severity of the condition the person is going to have to live with. Originally, it was considered a fairly inactive by-product during the production of insulin. Studies have revealed that the c peptide has more uses than that. It also has anti- and pro-inflammatory properties depending on the levels at which it is produced. Therefore, maintaining the optimal levels of c peptide is vital. 

The c peptide test uses are plenty:

  1. Measure of insulin made in the body – For a diabetes diagnosis, it would be essential to know how much insulin is being made in the body. This test can give an accurate measure of that amount
  2. T1D and T2D – The conditions differ in the sense that in T1D, insulin is not produced in the body at all. Whereas T2D, which is a metabolic condition, does have some production of insulin but the hormone produced is not used well. The test is a brilliant guide that helps to distinguish between these two conditions and prevent any misdiagnosis.
  3. Monitor diabetes – Even if you have been living with diabetes for a while, regular c peptide type 1 diabetes tests can help regulate the insulin dosage. 
  4. Hypoglycemia – The levels obtained by the test can also give a thorough insight into understanding the reason for low blood sugars. 
  5. Other major conditions – In case of a tumor in the pancreas, or to monitor the situation related to any pancreatic issue, this test can be of help.

Also read about urine sugar level

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How is a C-Peptide Test Administered? 

To understand the c peptide levels in type 2 diabetic patients or T1Ds, the test would have to be administered. It is a blood test that would require a blood sample that can be collected by any trained medical professional or path lab technician. The blood is drawn from a vein in the arm and can cause minor discomfort like in any other blood test. The collected blood will then be sent for analysis at the lab.

In case c peptide levels are measured via urine analysis, the sample collected over 24 hours is tested. 

What is a Normal C-Peptide Level?

As seen, it is important to maintain a c peptide normal range. This will help to have an understanding of the levels to be kept in check. 

  • The normal range for c peptide levels at the fasting stage would be 0.8-3.85 ng/mL
  • The low range for c peptide would be below 0.6 ng/mL and this could be an indication of cell failure or the diagnosis of T1D
  • These levels are said to increase after meals, just like insulin and that is normal.

Symptoms & Causes of Low C-Peptide Levels?


As in T1D, the symptoms of low levels of this product would be:

  • Excessive Thirst
  • Increased hunger
  • Large production and frequent passage of urination
  • Anxiety
  • Shaking and dizziness


  • Diagnosis of Type 1 diabetes
  • Diagnosis of Latent autoimmune diabetes in adults 
  • Diagnosis of Type 2 diabetes.
  • Prediabetes
  • Hypoglycemia
  • Fasting for a long time
  • Imperfectly functioning of the pancreas
  • Removal of the pancreas


Low C Peptide Levels in Type 1 Diabetes are very common and can cause several other health concerns as well

1. Inflammation

C-peptide has anti-inflammatory properties that can help with nerve pain, heart, and kidney function issues associated with diabetes. It also protects blood vessels from inflammation and helps to preserve the cognitive function

2. Fragile Bones

Lower levels might be linked with lower bone density and the development of osteoporosis.

Symptoms & Causes of High C-Peptide Levels?


An indicator that the body is producing too much insulin, the symptoms are-

  • Insulin resistance
  • Weight gain, increase in belly fat
  • Inflammation
  • High uric acid in the body
  • High cholesterol levels


  • Higher consumption of carbs/ increase in blood sugars
  • Insulin resistance
  • Obesity
  • Kidney-related distress
  • Cushing syndrome


High levels of c peptide in the body can lead to several effects on the health that may be damaging to the overall health and well-being

1. Insulin Resistance

If these levels are high, it means an increased production of insulin, often resulting in insulin resistance. Higher levels are often used as a predictor of insulin resistance

2. Metabolic Syndrome

This is a series of problems that are associated with the risk of developing T2D. High BP, blood sugar, excess body fat, etc

3. Heart Diseases

Hardening of arteries and development of heart diseases can be another effect of c peptide increase.


The importance of c peptide levels can be understood in this article. The information one can obtain from gaining an understanding of the level present in the body at a given time can be useful to rule out or diagnose different conditions that could affect the body. Keep an active lookout for any symptoms of high or low c peptide levels. Additionally, if you have been diagnosed with diabetes, ensure to get these levels tested regularly.


1. Do C-Peptide Levels fluctuate?

C peptide levels can fluctuate depending on the amount of insulin present and produced in the body. In case of a diagnosis of diabetes, these levels would be low and may not fluctuate much

2. What does a High C-peptide Level indicate?

A High Level means that the body is producing too much insulin. This could mean the diagnosis of T2D, insulin resistance, inflammation, etc.

3. What is considered a Low C-Peptide Level?

A Low Level would be anything below 0.6 ng/mL 

4. Is C-Peptide Low in Type 2 Diabetes?

No, in T2D, the body is unable to use the insulin produced by the body efficiently. This means that the production of C-Peptide is generally higher than normal. 

5. What Foods increase C-Peptide?

Any food that is high in carbs or sugar that might raise the levels and production of insulin in the body could also give rise to the C- Peptide. 


This website's content is provided only for educational reasons and is not meant to be a replacement for professional medical advice. Due to individual differences, the reader should contact their physician to decide whether the material is applicable to their case.