Insulin, Timed Challenge, Serum/Plasma — Substance Concentration
Measures insulin in blood before and after a timed challenge to assess insulin secretion and how the body regulates blood glucose.
["This test shows how the body releases insulin in response to a controlled challenge and may help evaluate diabetes or insulin resistance."]
Key facts at a glance
- LOINC
- 25697-4
- Short code
- Insulin sp7 p chal SerPl-sCnc
- Synonyms
- Insulin sp7 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 blood test measures the amount of insulin in serum or plasma at one or more specified times during a challenge. The results can show how effectively the body releases insulin in response to a controlled stimulus.
Why might I need this test?
A timed insulin test may be used to evaluate insulin secretion when diabetes, insulin resistance, or another condition affecting glucose regulation is suspected. It may also be ordered alongside glucose measurements.
How is the test performed?
A blood sample is collected before and, depending on the protocol, at set intervals after a standardized challenge. Each sample is tested to determine the insulin concentration, and the timing of every sample is important.
How do I prepare for the test?
Preparation varies by the specific challenge. Follow the ordering clinician's instructions about fasting, food or drink intake, medications, and the required test duration. If the timing is unclear, contact the laboratory before the test.
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 levels that are higher or lower than expected may reflect reduced insulin secretion, insulin resistance, or an altered response to the challenge. Results must be interpreted with the glucose measurements, timing, medical history, and laboratory reference intervals because a single insulin value is not enough to diagnose a condition.
Short name
Timed insulin challenge test
Frequently asked questions
Is this the same as a routine insulin blood test?
Does the test require fasting?
Why are several blood samples collected?
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