Proinsulin, Serum/Plasma — Substance Concentration
Measures proinsulin, an insulin precursor, in blood to help assess pancreatic insulin production and secretion.
["Proinsulin testing can help evaluate how the pancreas makes and releases insulin, usually alongside glucose and insulin results."]
Key facts at a glance
- LOINC
- 65352-7
- Short code
- Proinsulin sp1 p chal SerPl-sCnc
- Synonyms
- Proinsulin sp1 p chal SerPl-sCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 2.6
- Ref high
- 24.9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83525
- SNOMED
- 413618004
- 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
What is this test?
This blood test measures the amount of proinsulin in serum or plasma. Proinsulin is formed when the pancreas makes insulin and is then split into insulin and C-peptide.
Why might I need this test?
The test may be used to investigate unusual insulin levels, difficulty controlling blood sugar, or symptoms that suggest excess insulin production. It is usually interpreted with tests such as fasting glucose, insulin, and C-peptide.
How is the test performed?
A blood sample is drawn and separated into serum or plasma in the laboratory. The proinsulin concentration is then measured using a laboratory assay.
How do I prepare for the test?
Follow your clinician's instructions about fasting and medication timing. If the test is ordered with insulin or glucose testing, fasting may be required; otherwise, preparation may be minimal.
Reference range
Fasting: 2.6-24.9 μIU/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated proinsulin may indicate increased pancreatic stress or impaired insulin processing and can be seen with impaired glucose regulation or type 2 diabetes. Levels may also rise when kidney function is reduced because proinsulin is not cleared as efficiently. Results should be interpreted with glucose, insulin, C-peptide, kidney function, and the clinical context rather than alone.
Short name
Proinsulin
Frequently asked questions
Is proinsulin the same as insulin?
Why is this test ordered with insulin and C-peptide?
Does an abnormal proinsulin result diagnose diabetes?
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