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Insulin, Serum (Mass Concentration)

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

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

Quick summary

["Insulin helps control how your body uses sugar for energy."]

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

Key facts at a glance

LOINC
30255-4
Short code
Insulin 45M p chal SerPl-aCnc
Synonyms
Insulin 45M 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 doctor may order this test to check for conditions like diabetes, insulin resistance, or to monitor treatment for blood sugar management. It can also help diagnose issues with your pancreas or adrenal glands.

What Does the Test Involve?

A blood sample is taken from a vein, usually in your arm. You may feel a small pinch when the needle is inserted, but the process is quick. The sample is sent to a lab for analysis.

What to Expect Before or After the Test

No special preparation is needed, but avoid eating or drinking anything (except water) for at least 8–12 hours before the test if instructed. Afterward, you can resume normal activities, though you may experience mild bruising or soreness at the injection site.

How the Results Are Interpreted

Results are compared to standard reference ranges, but exact values can vary by lab. Your doctor will discuss the results in the context of your overall health and symptoms.

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

Serum Insulin

Frequently asked questions

What Are Common Causes of Abnormal Results?
High insulin levels may suggest insulin resistance, tumors producing insulin, or recent eating. Low levels could indicate diabetes, adrenal insufficiency, or pancreatic issues.
How Might My Doctor Use These Results?
Your doctor may use insulin levels to diagnose diabetes, evaluate hypoglycemia, or assess metabolic disorders. They may also compare results with glucose tests to understand how your body processes sugar.
Can I Fast Before This Test?
Yes, fasting is often required (typically 8–12 hours) to get an accurate measurement of insulin in your blood. Follow your doctor’s instructions to avoid misleading 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