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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. Insulin is a hormone produced by your pancreas that 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
12766-2
Short code
Insulin 45M p chal SerPl-mCnc
Synonyms
Insulin 45M 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 This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like unusual hunger, fatigue, weight changes, or signs of high or low blood sugar. It may also be used to diagnose or monitor conditions such as diabetes, hypoglycemia, or insulin resistance.

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 study. Bring any medications you’re currently taking.

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 levels accurately.

What the Results Mean

Results are interpreted based on your clinical context, symptoms, and other test results. Abnormal levels may indicate conditions like diabetes, insulinoma, or reactive 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

Insulin Level

Frequently asked questions

How often should I get this test?
Your provider will determine the frequency based on your health needs. For example, people with diabetes may test more often than others.
What causes insulin levels to change?
Insulin levels can fluctuate due to diet, exercise, stress, medications, or underlying health conditions like diabetes or pancreatic disorders.
Can I eat or drink before this test?
If fasting is required, follow your provider’s instructions. If not, avoid caffeine or sugary drinks that could affect 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