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Insulin, Serum Concentration (Quantitative)

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

This test measures the amount of insulin in your blood serum, which helps assess how your body uses sugar (glucose) for energy.

Quick summary

["Insulin levels help diagnose or monitor diabetes and other metabolic conditions."]

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

Key facts at a glance

LOINC
55386-7
Short code
Insulin 2M p chal SerPl-sCnc
Synonyms
Insulin 2M 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 resistance, or other hormonal imbalances. It can also help evaluate how well your body is responding to diabetes treatments or identify rare conditions like insulinoma (a tumor producing excess insulin).

What to Expect Before the Test

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

How the Test Is Performed

A blood sample is drawn from a vein, usually in your arm, using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The sample is sent to a lab for analysis using an immunoassay method to detect insulin.

What the Results Mean

Results are interpreted by your healthcare provider based on your symptoms, medical history, and other test results. Abnormally high or low levels may signal conditions like diabetes, hypoglycemia, or pancreatic 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.

◆Associated findings1

Short name

Insulin Level

Frequently asked questions

What causes abnormal insulin levels?
Abnormal insulin levels can result from conditions like diabetes (either too much or too little insulin), pancreatic tumors (e.g., insulinoma), certain medications (e.g., steroids), or metabolic disorders. Lifestyle factors such as diet, exercise, and obesity also influence insulin sensitivity.
How often should I get this test?
Your doctor will determine how often you need this test based on your health status. For example, people with diabetes may need regular monitoring, while others may only require it during specific evaluations (e.g., pregnancy, suspected metabolic disorders). Follow their guidance.
Can I eat or drink before this test?
If fasting is required (e.g., for a glucose challenge), avoid food and liquids except water for the specified period. If no fasting is needed, you can eat and drink normally, but check with your lab or doctor for exact instructions.
  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