Insulin, Serum/Plasma — Analyte Concentration
Measures the amount of insulin in a blood sample, helping evaluate blood sugar regulation and possible symptoms of high or low blood sugar.
["This blood test shows how much insulin is circulating at the time the sample is collected."]
Key facts at a glance
- LOINC
- 20448-7
- Short code
- Insulin SerPl-aCnc
- Synonyms
- Insulin 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?
An insulin blood test measures the concentration of insulin, a hormone made by the pancreas that helps glucose enter cells for energy. The result is most useful when interpreted together with a simultaneous blood glucose test and the clinical situation.
Why might I need this test?
This test may be ordered to investigate unexplained high or low blood sugar, evaluate suspected diabetes or insulin resistance, or help assess symptoms such as sweating, shakiness, weakness, or increased thirst. It may also be used in certain medical conditions or when monitoring specific treatments.
How is the test performed?
A blood sample is drawn from a vein and separated into serum or plasma. The laboratory then measures the insulin concentration, often using an immunoassay.
How do I prepare for the test?
Follow the instructions provided by your healthcare professional. Fasting may be required, and the timing of the blood draw is important because insulin and glucose levels naturally change after meals. Do not stop insulin or other diabetes medicines unless your clinician directs 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 unexpectedly high or low, particularly when measured alongside blood glucose, may help identify problems with insulin production, insulin resistance, or blood sugar regulation. High insulin with high glucose can suggest insulin resistance, while low insulin with high glucose may be consistent with insufficient insulin production. Results must be interpreted by a healthcare professional because insulin levels vary with meals, medications, and the timing of the sample.
Short name
Insulin
Frequently asked questions
Is fasting required for an insulin blood test?
What does a high insulin level mean?
Can this test diagnose diabetes?
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