Insulin, Serum/Plasma — 8-Hour Timed Concentration
Measures insulin in a serum or plasma sample collected at a specified time, usually as part of evaluating glucose metabolism.
["This timed insulin test is interpreted together with blood glucose, symptoms, medications, and the timing of the sample."]
Key facts at a glance
- LOINC
- 50508-1
- Short code
- Insulin sp8 SerPl-aCnc
- Synonyms
- Insulin sp8 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 a blood sample. Insulin is a hormone made by the pancreas that helps glucose enter cells for energy. The test code indicates a timed collection; confirm with your care team whether the sample is meant to be taken 8 hours after eating or after a glucose load.
Why might I need this test?
A timed insulin test may be used to evaluate how the body responds to food or glucose. Your clinician may order it when investigating diabetes, insulin resistance, unusually high or low blood glucose, or symptoms related to low glucose.
How is the test performed?
A blood sample is drawn and separated into serum or plasma by the laboratory. Insulin is then measured using a laboratory assay. The result depends on the exact collection time and whether it follows a meal, fasting, or an oral glucose tolerance test.
How do I prepare for the test?
Follow the timing instructions provided by your clinician or laboratory, including any instructions about fasting or eating. The timing of insulin injections, diabetes medicines, and meals can affect the result, so tell the care team about them and do not stop prescribed medicines unless instructed.
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 higher than expected for the collection conditions may occur with insulin resistance, obesity, metabolic syndrome, or after a glucose load. Insulin lower than expected, especially when glucose is high, may indicate that the pancreas is not producing enough insulin. A high insulin level together with low glucose may raise concern for excess insulin, including administered insulin, so results must be interpreted by a clinician using the timing and clinical context.
Short name
Timed insulin test
Frequently asked questions
Does one insulin result diagnose diabetes?
Why does the collection time matter?
Should I stop taking insulin before this 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