Insulin, Serum/Plasma — Concentration
Measures the amount of insulin in a blood sample. Results may help evaluate blood sugar regulation, insulin resistance, and the cause of high or low glucose.
["An insulin blood test can help assess how well the body regulates blood sugar."]
Key facts at a glance
- LOINC
- 33817-8
- Short code
- Insulin sp3 p chal SerPl-aCnc
- Synonyms
- Insulin sp3 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 glucose enter cells for energy. The sample is analyzed as serum or plasma, depending on the laboratory method.
Why might I need this test?
Your clinician may order an insulin test when evaluating diabetes, insulin resistance, unexplained high or low blood sugar, or symptoms that may be related to too much or too little insulin. It may also be used with other laboratory tests to assess the body's response to food or glucose.
How is the test performed?
A blood sample is drawn from a vein and processed in the laboratory. Insulin is usually measured using an immunoassay, and the result is reported as a concentration.
How do I prepare for the test?
Follow your clinician's instructions about fasting and meal timing. A fasting insulin test is commonly collected after an overnight fast, but timing may differ for other insulin tests. Do not stop diabetes medicines or change insulin doses 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.
Higher insulin levels may occur with insulin resistance, metabolic syndrome, type 2 diabetes, or after receiving insulin. Lower insulin levels with elevated glucose may suggest that the pancreas is not producing enough insulin. Results must be interpreted with glucose symptoms, medical history, medicines, and other laboratory tests.
Short name
Insulin
Frequently asked questions
Does an insulin test diagnose diabetes?
Do I need to fast before this test?
What if my insulin result is abnormal?
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