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Proinsulin, Serum/Plasma — Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

A blood test that measures proinsulin, a precursor of insulin, to help evaluate pancreatic beta-cell function and insulin production.

Quick summary

["Proinsulin testing can help assess how the pancreas produces and releases insulin."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
17491-2
Short code
Proinsulin BS SerPl-mCnc
Synonyms
Proinsulin BS SerPl-mCnc
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 made by the pancreas and is partly processed into insulin. This test measures the amount of proinsulin in serum or plasma. It is usually interpreted with glucose and insulin measurements.

Why might I need this test?

A clinician may order this test when evaluating diabetes, insulin resistance, or unusually high or low insulin levels. It may also be used in the evaluation of certain pancreatic conditions.

How is the test performed?

A blood sample is collected from a vein and separated into serum or plasma. The laboratory then measures the amount of proinsulin in the sample.

How do I prepare for the test?

Fasting may be required, especially when proinsulin is being checked with glucose and insulin. Follow your clinician's instructions and tell the laboratory if you have recently taken insulin or other diabetes medicines.

Reference range

Fasting: 2.6-24.9 μIU/mLN/A

Specimen: serum

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.

◆Associated findings1

Short name

Proinsulin

Frequently asked questions

Is proinsulin the same as insulin?
No. Proinsulin is an inactive precursor that the pancreas partly converts into insulin. A small amount of proinsulin normally remains in the blood.
Is this a routine diabetes test?
It is not usually a routine stand-alone screening test. It is more often used when a clinician needs a more detailed assessment of insulin production.
Do I need to fast before the test?
That depends on the reason for the test and the instructions provided by your clinician. Fasting is commonly requested when proinsulin is measured along with insulin and glucose.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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