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Serum Insulin Concentration (Quantitative)

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

This test measures the amount of insulin in your blood, which helps regulate blood sugar levels. Insulin is a hormone produced by your pancreas.

Quick summary

["Insulin levels help diagnose and monitor conditions like diabetes or insulin resistance."]

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

Key facts at a glance

LOINC
55388-3
Short code
Insulin 4h p chal SerPl-sCnc
Synonyms
Insulin 4h 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

Why Is This Test Done?

Your doctor may order this test to check for diabetes, insulin production issues, or other metabolic disorders. It can also help evaluate how well your body responds to insulin or diagnose conditions like hypoglycemia (low blood sugar).

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a glucose tolerance or fasting insulin panel. Bring any medications you’re currently taking to your appointment.

How the Test Is Performed

A blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab for analysis using an immunoassay method to detect insulin concentration.

What the Results Mean

Results are interpreted based on your overall health, symptoms, and other test results. Abnormal levels may indicate diabetes, insulin resistance, or other endocrine disorders. Your doctor will discuss findings with you.

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.

Clinical Significance

Short name

Insulin Level

Frequently asked questions

High insulin levels may suggest insulin resistance, pancreatic tumors, or other endocrine disorders, while low levels could indicate diabetes, pancreatic issues, or medications affecting insulin production.
This test is often used alongside glucose measurements to diagnose or monitor diabetes and related conditions. It helps assess how your body manages blood sugar over time.
What if I Have Questions About My Results?
If your results are unclear, ask your doctor to explain them in detail. They can also clarify whether additional testing is needed.
Does fasting affect this test?
Yes, fasting may influence insulin levels, so follow your doctor’s instructions for preparation. If fasting is required, avoid eating or drinking anything except water for the specified period.
  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