Insulin, Serum/Plasma — Substance Concentration
Measures the amount of insulin in a blood sample to help evaluate blood sugar control, insulin production, and possible insulin resistance.
["This blood test shows how much insulin is present and is interpreted together with your blood glucose and medical history."]
Key facts at a glance
- LOINC
- 25699-0
- Short code
- Insulin sp9 p chal SerPl-sCnc
- Synonyms
- Insulin sp9 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 insulin, a hormone made by the pancreas that helps glucose move from the bloodstream into cells for energy. The result may be reported from a serum or plasma blood sample.
Why might I need this test?
Insulin testing may be used when diabetes, low blood sugar, insulin resistance, or unusual insulin levels are being evaluated. It may also be measured during a glucose tolerance test to see how the body responds to sugar.
How is the test performed?
A healthcare professional draws blood into a tube, and the laboratory measures the insulin concentration in the serum or plasma. If the test is part of a glucose challenge, blood may be collected at specific times before and after you drink a glucose solution.
How do I prepare for the test?
Follow the fasting and timing instructions provided by your clinician. If timed samples are required, remain at the testing location as directed. Do not stop insulin or other diabetes medicines unless your clinician specifically instructs 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.
Insulin results must be interpreted with the blood glucose level and the conditions of the test. More insulin than expected may occur with insulin resistance or high blood sugar, while less insulin than expected may suggest reduced insulin production. Unexpectedly high insulin with low blood sugar can sometimes result from injected insulin or an insulin-producing condition and should be evaluated by a clinician.
Short name
Serum/Plasma Insulin
Frequently asked questions
Is this the same as a fasting glucose test?
Does a high insulin result always mean I have diabetes?
Why are multiple insulin measurements sometimes needed?
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