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Insulin, Serum (Quantitative)

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

This test measures the amount of insulin, a hormone produced by your pancreas, in your blood serum. It helps assess how your body regulates blood sugar levels.

Quick summary

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

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

Key facts at a glance

LOINC
57353-5
Short code
Insulin 5M p chal SerPl-aCnc
Synonyms
Insulin 5M p chal 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

Why Is This Test Done?

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

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 insulin sensitivity study. Bring any medications you’re taking to your appointment.

How the Test Is Done

A healthcare professional will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis using an immunoassay method to measure insulin concentration.

What the Results Mean

Results are interpreted based on your overall health, symptoms, and medical history. Elevated insulin levels may suggest insulin resistance or other endocrine disorders, while very low levels could indicate diabetes or other metabolic issues.

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

What does my insulin level tell me about my health?
High insulin levels might indicate insulin resistance, prediabetes, or conditions like polycystic ovary syndrome (PCOS). Low levels could signal diabetes, adrenal insufficiency, or other hormonal imbalances. Always discuss results with your provider for personalized guidance.
How often should I get this test?
Your provider will determine the frequency based on your medical needs. Regular monitoring may be recommended if you have diabetes, prediabetes, or other conditions affecting insulin function.
Can I take anything before or after the test?
If fasting is required, avoid food or drink (except water) for the specified period. After the test, you can resume normal activities, but follow any specific instructions from your healthcare team.
  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