Insulin, Third Post-Challenge Specimen, Serum/Plasma — Mass Concentration
Measures insulin in the third scheduled blood specimen after a glucose challenge. Serum or plasma is tested, and the result is reported as a mass concentration.
["This test measures the pancreas's insulin response at a scheduled point after a glucose challenge."]
Key facts at a glance
- LOINC
- 12740-7
- Short code
- Insulin sp3 p chal SerPl-mCnc
- Synonyms
- Insulin sp3 p chal SerPl-mCnc
- 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 blood at the third scheduled collection after a controlled glucose challenge. Insulin is a hormone made by the pancreas that helps cells use glucose for energy.
Why might I need this test?
Post-challenge insulin testing may be used to evaluate how effectively the pancreas releases insulin in response to glucose. It may be ordered alongside blood glucose measurements to help assess carbohydrate metabolism and select or monitor diabetes treatment.
How is the test performed?
A blood sample is collected at the specified point after the glucose challenge and tested for insulin using a laboratory assay. The result may be reported from serum or plasma, and the collection time and accompanying glucose result are important for interpretation.
How do I prepare for the test?
Follow the timing and dietary instructions provided by the ordering clinician or testing facility. Glucose challenge testing is commonly performed after an overnight fast, and insulin or other diabetes medicines may need to be temporarily held only if your clinician 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.
A strong rise in insulin after the glucose challenge generally indicates that the pancreas is responding to glucose. Little or no insulin rise despite an elevated glucose level may suggest impaired insulin secretion, while unusually high insulin with low glucose may suggest excess insulin production or administered insulin. Interpretation depends on the paired glucose results, collection timing, symptoms, medications, and the specific testing protocol.
Short name
Post-challenge insulin
Frequently asked questions
What is a post-challenge insulin test?
Do I need to fast before this test?
Why are insulin and glucose results reviewed together?
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