Insulin, Serum/Plasma — Substance Concentration
A blood test that measures insulin levels to help evaluate pancreatic function and investigate abnormalities in blood glucose.
["Insulin testing helps show how effectively the body regulates blood sugar."]
Key facts at a glance
- LOINC
- 25698-2
- Short code
- Insulin sp8 p chal SerPl-sCnc
- Synonyms
- Insulin sp8 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 test measures the amount of insulin in a blood sample. Insulin is a hormone made by the pancreas that helps glucose enter cells for energy.
Why might I need this test?
Your clinician may order insulin testing to evaluate pancreatic function, investigate episodes of low blood sugar, or assess how your body responds to glucose. It may be used alongside glucose, C-peptide, and other diabetes tests.
How is the test performed?
A blood sample is drawn from a vein and analyzed by a laboratory method. If insulin is being measured as part of a glucose challenge or another timed test, samples may be collected before and after a specified stimulus.
How do I prepare for the test?
Follow your clinician's instructions about fasting and the timing of the test. Fasting insulin tests commonly require no food for about 8 to 12 hours, while water is usually allowed. Do not stop insulin or other medicines unless your clinician tells you to do so.
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 higher or lower than expected may reflect differences in pancreatic function, food intake, stress, physical activity, or medication effects. When interpreted with glucose and other laboratory results, it can help clarify why blood sugar is too high or too low. A single insulin result is generally not enough to diagnose diabetes or another condition by itself.
Short name
Insulin
Frequently asked questions
Does this test diagnose diabetes?
Why might insulin be measured before and after a glucose drink?
Do I need to stop taking insulin 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