Insulin, Serum/Plasma — Timed Post-Carbohydrate Challenge, Substance Concentration
Measures insulin in blood at a specified time after a carbohydrate challenge to evaluate how the pancreas responds to increased blood glucose.
["This timed insulin test helps evaluate pancreatic insulin release and the body's response to a carbohydrate load."]
Key facts at a glance
- LOINC
- 25687-5
- Short code
- Insulin sp12 p chal SerPl-sCnc
- Synonyms
- Insulin sp12 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. When it is collected as a timed post-carbohydrate test, the result shows how the pancreas responds after you drink a glucose-containing beverage.
Why might I need this test?
A timed insulin test may help evaluate insulin resistance, diabetes, or episodes of low blood glucose. It may be used alongside glucose measurements and other tests to assess how insulin and blood glucose change together.
How is the test performed?
A blood sample is collected at the exact interval specified by the laboratory. During a carbohydrate challenge test, you usually drink a measured glucose beverage, and blood is drawn at one or more scheduled times; your insulin result should be interpreted with the corresponding glucose results.
How do I prepare for the test?
Follow the laboratory's instructions about fasting, the carbohydrate challenge, and the exact collection time. Take medicines only as directed, and tell the healthcare team if you have recently used insulin or other glucose-lowering medicines.
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 that remains elevated relative to glucose during the challenge may suggest reduced insulin sensitivity, which can occur with obesity, prediabetes, or type 2 diabetes. Insulin that is unexpectedly low or falls too far may contribute to low blood glucose. Results depend heavily on collection timing, symptoms, medicines, and the simultaneous glucose measurement.
Short name
Insulin
Frequently asked questions
Is this the same as a routine insulin test?
Why are insulin and glucose measured together?
Does the 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