Proinsulin (Serum)
This test measures the amount of proinsulin, a precursor protein of insulin, in your blood. It helps assess how well your pancreas is producing insulin and can be useful in diagnosing or monitoring certain diabetes-related conditions.
["Proinsulin levels can help detect early insulin issues and support diabetes management."]
Key facts at a glance
- LOINC
- 108143-9
- Short code
- C peptide sp3 SerPl-mCnc
- Synonyms
- C peptide sp3 SerPl-mCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order a proinsulin test if you have symptoms of diabetes, such as frequent urination, excessive thirst, or unexplained weight loss. It can also be used to evaluate insulin production in people with type 1 or type 2 diabetes, especially when insulin resistance or other complications are suspected. Rarely, it may be used in research or specialized clinical settings to assess pancreatic function in non-diabetic individuals.
What Does the Test Involve?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure proinsulin levels. This test is typically done as part of a larger panel or independently based on clinical needs.
What to Expect Before the Test
No special preparation is usually required, but you may be asked to fast for 8–12 hours before the test if it is part of a fasting glucose or insulin sensitivity study. Always follow your healthcare provider’s instructions.
What to Expect During the Test
You will lie down comfortably while a healthcare professional inserts a small needle into your arm to draw blood. The process is quick and typically causes only minor discomfort. You may feel a slight pinch or sting, but most people tolerate it well.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Proinsulin Level
Frequently asked questions
What does a proinsulin test measure?
Is fasting required for this test?
How long does it take to get results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy