Insulin, Serum/Plasma — Concentration
Measures the amount of insulin in blood. It may be used with glucose testing to evaluate pancreatic insulin production and insulin resistance.
["Insulin blood testing helps show how well the body regulates blood sugar and produces insulin."]
Key facts at a glance
- LOINC
- 33815-2
- Short code
- Insulin sp1 p chal SerPl-aCnc
- Synonyms
- Insulin sp1 p chal SerPl-aCnc
- 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 test measures insulin, a hormone made by the pancreas that helps cells take up glucose for energy. The sample is usually collected from a vein and analyzed as serum or plasma.
Why might I need this test?
Insulin may be measured when hypoglycemia, diabetes, or symptoms of excess insulin are being evaluated. It is often interpreted together with a glucose level, particularly during an oral glucose tolerance test or when insulin resistance is suspected.
How is the test performed?
A blood sample is drawn and the laboratory measures the concentration of insulin in the serum or plasma. If the test is part of a timed glucose challenge, the sample must be collected at the exact time specified by the laboratory.
How do I prepare for the test?
Follow the instructions provided by your healthcare professional. The test may be done while fasting or at a specified time after eating or receiving glucose, and eating or drinking during the collection period may affect the result.
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.
An insulin level that is high when blood glucose is low may indicate excessive insulin production, which can occur with an insulin-secreting tumor or certain medicines. High insulin with elevated or normal glucose can be associated with insulin resistance. Low insulin in the setting of high glucose may indicate that the pancreas is not producing enough insulin. Results must be interpreted with glucose levels, symptoms, medications, and other tests.
Short name
Insulin
Frequently asked questions
Does this test diagnose diabetes?
Why might my insulin and glucose results be checked together?
Do I need to fast before an insulin 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