Proinsulin, Serum/Plasma — Substance Concentration
A blood test that measures proinsulin, a precursor of insulin, to help assess how the pancreas produces and processes insulin.
["Proinsulin is usually interpreted with glucose, insulin, and C-peptide to help evaluate pancreatic insulin production and unexplained hypoglycemia."]
Key facts at a glance
- LOINC
- 47190-4
- Short code
- Proinsulin BS SerPl-sCnc
- Synonyms
- Proinsulin BS 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?
Proinsulin is an inactive precursor that pancreatic beta cells convert into insulin. This blood test measures the amount of proinsulin in serum or plasma.
Why might I need this test?
Your clinician may order it when evaluating diabetes, insulin resistance, or episodes of low blood sugar. It is often interpreted with insulin, C-peptide, and glucose measurements.
How is the test performed?
A blood sample is collected by venipuncture and analyzed in a laboratory. The blood is separated into serum or plasma, depending on the laboratory method, so the proinsulin level can be measured.
How do I prepare for the test?
Fasting is usually not required, but fasting may be requested when this test is ordered with other insulin-related tests. Follow your clinician's instructions and tell the laboratory if you recently had low blood sugar or received insulin.
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.
A high proinsulin level may occur when the pancreas is producing more insulin precursor than the body can process, which can be associated with insulin resistance or impaired beta-cell function. A low level may reflect reduced insulin production. Results vary with blood glucose, kidney function, and insulin treatment, so they should be interpreted by a clinician in your overall clinical context.
Short name
Proinsulin
Frequently asked questions
Is proinsulin the same as insulin?
Why is this test checked during low blood sugar episodes?
Do I need to fast before the test?
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