Insulin, Serum/Plasma — Concentration
This blood test measures the amount of insulin, a hormone that helps glucose enter cells for energy.
["The insulin level helps evaluate how the body regulates blood sugar."]
Key facts at a glance
- LOINC
- 50505-7
- Short code
- Insulin sp5 SerPl-aCnc
- Synonyms
- Insulin sp5 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, which is the liquid portion of a blood sample. Insulin is made by the pancreas and helps lower blood glucose by allowing glucose to enter cells.
Why might I need this test?
A clinician may order an insulin test to help assess blood sugar regulation, investigate symptoms of unusually high or low glucose, or monitor diabetes treatment. It may be measured alone or alongside glucose and other diabetes tests.
How is the test performed?
A blood sample is collected and sent to a laboratory, where the amount of insulin is measured using a validated laboratory assay. Your clinician will interpret the result in relation to your glucose levels, symptoms, medications, and medical history.
How do I prepare for the test?
Follow your clinician's preparation instructions. If the test is ordered as a fasting test, you may be asked to avoid food and drinks other than water for the specified period. Do not change insulin or other diabetes medications 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.
An insulin level that is higher than expected may occur when blood glucose is low, during physical or emotional stress, or in people who are overweight or have insulin resistance. A lower-than-expected level may occur after fasting, with certain medications, or when the pancreas does not produce enough insulin. Results should be interpreted with glucose measurements and the rest of your clinical evaluation.
Short name
Insulin
Frequently asked questions
Does this test diagnose diabetes?
Why are insulin and glucose tested at the same time?
Does the insulin blood test require fasting?
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