Insulin, Serum/Plasma — Concentration
Measures insulin levels in a blood sample. The result may be interpreted with blood glucose to help evaluate how the body regulates blood sugar.
["An insulin blood test can help assess pancreatic insulin production and how the body handles blood sugar."]
Key facts at a glance
- LOINC
- 50503-2
- Short code
- Insulin sp3 SerPl-aCnc
- Synonyms
- Insulin sp3 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 the amount of insulin in serum or plasma, the liquid portion of blood. Insulin is a hormone made by the pancreas that helps glucose enter cells for energy.
Why might I need this test?
Your doctor may order this test when evaluating unusually high or low blood glucose, symptoms that may suggest excess or insufficient insulin, or possible problems with pancreatic function. It may also be used to monitor certain diabetes treatments.
How is the test performed?
A blood sample is collected from a vein and sent to a laboratory for measurement. The result is often considered alongside a blood glucose test from the same sample.
How do I prepare for the test?
Preparation depends on why the test was ordered. Fasting may be requested, and the timing of the blood draw can be important because meals and recent insulin use affect the result. Follow your doctor's instructions and tell the laboratory about insulin injections or other diabetes medicines.
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 than expected may occur with high blood glucose, reduced insulin sensitivity, or after certain medications. A lower-than-expected level may occur with low blood glucose, reduced food intake, or excessive insulin effect. Insulin should be interpreted with glucose and other clinical findings because a single value does not establish a diagnosis by itself.
Short name
Insulin Blood Test
Frequently asked questions
Does a high insulin result always mean I have diabetes?
Why might my doctor order insulin and glucose tests together?
Can insulin levels be affected by eating or taking insulin?
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