Insulin, Serum/Plasma — 15-Minute Post-Challenge Concentration
Measures insulin in blood 15 minutes after a glucose challenge to help evaluate the pancreas's early insulin response.
["This timed insulin measurement is interpreted with the accompanying glucose results to assess how well the body responds to a glucose challenge."]
Key facts at a glance
- LOINC
- 33814-5
- Short code
- Insulin sp15 p chal SerPl-aCnc
- Synonyms
- Insulin sp15 p chal 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 in serum or plasma 15 minutes after a glucose challenge. Insulin is a hormone made by pancreatic beta cells that helps the body take up glucose for energy.
Why might I need this test?
A 15-minute insulin measurement may be included with a glucose challenge or glucose tolerance test. It helps clinicians evaluate the body's early insulin response and may be used when evaluating abnormal glucose levels or suspected problems with insulin secretion.
How is the test performed?
Blood is collected 15 minutes after the challenge. Timing is important because insulin changes rapidly after glucose is given. The insulin result is usually interpreted along with glucose measurements taken before and after the challenge.
How do I prepare for the test?
Follow the preparation instructions provided by the testing clinic. Some glucose challenge tests require an overnight fast, but the rules may differ if this insulin test is ordered as part of another procedure. Do not change medications or restrict food unless 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 higher-than-expected early insulin response may be seen with insulin resistance or an exaggerated insulin secretory response. A lower or delayed response may indicate impaired pancreatic beta-cell function, although recent insulin use and other factors can also affect the result. The insulin value should be interpreted with the glucose results and the full clinical picture rather than by itself.
Short name
15-minute post-challenge insulin
Frequently asked questions
Why is the blood sample collected exactly 15 minutes after the challenge?
Do I need to fast before this test?
Can one insulin result diagnose diabetes?
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