Insulin, Serum/Plasma — 15-Minute Post-Challenge Substance Concentration
A timed blood test measuring insulin after a carbohydrate challenge, used with glucose results to evaluate how the body handles glucose and insulin.
["This timed insulin test helps assess insulin response to a carbohydrate challenge and is interpreted together with glucose levels."]
Key facts at a glance
- LOINC
- 25690-9
- Short code
- Insulin sp15 p chal SerPl-sCnc
- Synonyms
- Insulin sp15 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 the amount of insulin in a blood sample collected 15 minutes after a carbohydrate challenge. Insulin is a hormone that helps cells take up glucose for energy.
Why might I need this test?
A timed insulin measurement may be used to evaluate insulin response, particularly when diabetes, insulin resistance, or abnormal glucose levels are being assessed. The result is usually interpreted with glucose measurements and the person's medical history.
How is the test performed?
A blood sample is collected according to a timed testing protocol, often before and after a measured carbohydrate or glucose challenge. The laboratory then measures the insulin concentration in the sample.
How do I prepare for the test?
Follow the laboratory's instructions about the carbohydrate challenge, fasting, and exact collection time. Do not change insulin or other diabetes medicines unless your healthcare professional tells 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.
An insulin level that is unexpectedly high or low may reflect differences in insulin production, insulin resistance, or the timing of the sample. Interpretation depends on the challenge, collection time, glucose results, medications, and other clinical findings, so the value should be reviewed by a healthcare professional.
Short name
15-minute post-challenge insulin
Frequently asked questions
Is this the same as a routine fasting insulin test?
Why are several blood samples collected?
Do I need to stop taking insulin before the 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