Insulin, Serum/Plasma — Mass Concentration
This blood test measures insulin levels in serum or plasma to help assess insulin production and how the body handles glucose.
["Insulin testing helps clinicians evaluate glucose regulation, insulin resistance, and the body's ability to produce insulin."]
Key facts at a glance
- LOINC
- 12743-1
- Short code
- Insulin sp6 p chal SerPl-mCnc
- Synonyms
- Insulin sp6 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 a blood sample. Insulin is a hormone made by the pancreas that helps glucose enter cells for energy.
Why might I need this test?
Insulin may be measured when diabetes, prediabetes, insulin resistance, or symptoms related to abnormal blood glucose are being evaluated. It is often interpreted together with a glucose level and may be paired with other tests, such as C-peptide.
How is the test performed?
A blood sample is collected, and the serum or plasma is separated for laboratory measurement. The result reports the insulin concentration in the blood.
How do I prepare for the test?
Fasting may be requested, but preparation depends on the reason for testing and your clinician's instructions. The timing of the test relative to meals and insulin or diabetes medications is important, so do not change or stop prescribed insulin without medical advice.
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 insulin level may occur with insulin resistance, type 2 diabetes, or after receiving insulin. A lower level may indicate reduced insulin production. Results must be interpreted with glucose levels, the time of the blood draw, and any relevant medications because food intake and treatment can affect insulin concentration.
Short name
Insulin
Frequently asked questions
Is a fasting blood sample required for insulin testing?
Why are insulin and glucose often checked together?
Does a high insulin result always mean I have 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