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Insulin, Serum/Plasma — Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

A blood test that measures insulin, the hormone that helps glucose enter cells and regulates blood sugar levels.

Quick summary

["This test shows how much insulin is present in the blood at the time the sample is collected."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
12746-4
Short code
Insulin sp9 p chal SerPl-mCnc
Synonyms
Insulin sp9 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 your blood. Insulin is made by the pancreas and helps move glucose into cells for energy.

Why might I need this test?

A clinician may use this test when evaluating diabetes, insulin resistance, or low blood sugar. It may also be used to understand how your body responds to meals, glucose, or diabetes medicines.

How is the test performed?

A blood sample is drawn from a vein and tested in a laboratory. The result reflects your insulin level at the time the sample was collected.

How do I prepare for the test?

Follow the preparation instructions provided by your clinician. This test is often performed while fasting, but timing and fasting requirements can vary by the specific order. Do not stop insulin or other diabetes medicines unless your clinician tells you to.

Reference range

Fasting: 2.6-24.9 μIU/mLN/A

Specimen: serum

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.

Higher insulin levels can occur with insulin resistance, type 2 diabetes, insulin use, or certain other medical conditions. Lower levels may occur with injected insulin, reduced food intake, or conditions affecting pancreatic insulin production. Results must be interpreted with your symptoms, medications, glucose levels, and the timing of the blood draw.

Short name

Insulin

Frequently asked questions

Does this test diagnose diabetes?
Usually, an insulin test is interpreted alongside blood glucose tests and other clinical information rather than used by itself to diagnose diabetes.
Do I need to fast before this test?
It depends on the instructions for your order. Fasting insulin is commonly requested, so confirm the required timing with your clinician or laboratory.
Why might my insulin level change from one test to another?
Insulin levels vary with meals, fasting, physical activity, stress, and medicines. The collection time and your current diabetes treatment are important when comparing results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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