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Insulin, Serum (Quantitative)

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

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

Quick summary

["Insulin levels help assess your body’s ability to use glucose for energy and identify potential diabetes or insulin-related conditions."]

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

Key facts at a glance

LOINC
12755-5
Short code
Insulin 11h p chal SerPl-mCnc
Synonyms
Insulin 11h p chal SerPl-mCnc
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 diagnose or monitor conditions like diabetes, insulin resistance, or other metabolic disorders. It can also help evaluate symptoms such as unexplained weight changes, fatigue, or frequent urination.

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 metabolic evaluation. Bring any medications you’re taking to your appointment.

During the Test

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are interpreted based on your overall health, symptoms, and medical history. High or low insulin levels may signal underlying issues that require further evaluation, such as insulin resistance or hypoglycemia.

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 Level

Frequently asked questions

What does insulin do in my body?
Insulin is a hormone that helps your body use glucose (sugar) for energy. Low levels may indicate problems with insulin production, while high levels can suggest conditions like insulinoma (a rare tumor) or resistance to insulin, which is common in prediabetes or type 2 diabetes.
How might my results affect my treatment?
Your doctor will use these results to adjust medications, lifestyle recommendations, or further testing if needed. For example, low insulin levels might prompt evaluation for diabetes or other endocrine disorders.
Can I get false results?
Possible factors like recent illness, stress, or certain medications could influence results. If you suspect an error, discuss your symptoms and medications with your provider before retesting.
  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