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Insulin, Serum/Plasma — Concentration

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

Measures the amount of insulin in blood, helping clinicians evaluate how well the body regulates blood sugar and produces insulin.

Quick summary

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

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

Key facts at a glance

LOINC
47669-7
Short code
Insulin pre Gc SerPl-aCnc
Synonyms
Insulin pre Gc 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, a hormone made by the pancreas that helps glucose enter cells for energy. The sample is usually tested as serum or plasma, depending on the laboratory.

Why might I need this test?

Your clinician may order this test when evaluating diabetes, insulin resistance, or symptoms related to low or high blood sugar. It may also be used to assess pancreatic insulin production or monitor certain diabetes treatments.

How is the test performed?

A blood sample is collected from a vein and processed in the laboratory. The result reflects your insulin level at the time of collection and is often interpreted together with a simultaneous glucose measurement.

How do I prepare for the test?

Fasting for several hours may be required, so follow your clinician's instructions. Do not stop prescribed diabetes medicines unless your healthcare professional tells you to, because medication, meals, exercise, and the timing of the blood draw can affect the result.

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.

◆Associated findings1

Short name

Insulin

Frequently asked questions

Does this test diagnose diabetes?
Not by itself. Insulin is usually interpreted along with blood glucose, symptoms, medical history, and sometimes other tests such as C-peptide.
Why might the test need to be repeated?
Repeat testing may be needed if the first result does not fit the clinical picture or if the level must be assessed under standardized conditions, such as before or after a glucose load.
Can medicines or food affect the result?
Yes. Insulin injections, some diabetes medicines, meals, and the time of day can change the insulin level, so preparation and timing are important.
  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