Insulin, Serum/Plasma — 4-Hour Timed Specimen, Analyte Concentration
Measures insulin in a serum or plasma blood sample. A 4-hour timed result may be used with glucose measurements to assess insulin response over time.
["This test measures how much insulin is present in the blood at a specified 4-hour time point."]
Key facts at a glance
- LOINC
- 50504-0
- Short code
- Insulin sp4 SerPl-aCnc
- Synonyms
- Insulin sp4 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 concentration of insulin, a hormone that helps move glucose from the bloodstream into cells for energy. The result is from a serum or plasma sample collected at a specified 4-hour time point.
Why might I need this test?
A timed insulin test may be ordered to evaluate how the body responds to glucose over several hours. It is usually interpreted with glucose results and may help a clinician assess blood sugar control, insulin resistance, or symptoms related to low or high blood sugar.
How is the test performed?
Blood is drawn from a vein and separated into serum or plasma. The laboratory then measures the insulin concentration using a validated testing method. If this is part of a glucose challenge, the blood must be collected at the exact time requested by the healthcare professional.
How do I prepare for the test?
Follow the timing and dietary instructions provided for the test. Some measurements require fasting, while others are part of a standardized glucose challenge. Tell your clinician if you have recently eaten, taken insulin, or other medicines that may affect the result.
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.
◆Associated findings1
Short name
Timed insulin test
Frequently asked questions
Does a high insulin level always mean I have diabetes?
Why does the timing of the blood draw matter?
Can I take my usual medicines 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