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Insulin, Serum (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. It helps assess how well your body is managing blood sugar levels.

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
2481-0
Short code
Insulin Ab Ser Ql
Synonyms
Insulin Ab Ser Ql
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 Is Done

Your doctor may order a serum insulin test to check for conditions like diabetes, hypoglycemia (low blood sugar), or insulinoma (a rare tumor that causes high insulin levels). It may also be used to evaluate how your body responds to insulin therapy or to investigate unexplained symptoms such as excessive hunger, fatigue, or weight changes.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test, especially if it’s part of a glucose-insulin profile. Bring any medications you’re taking to your doctor’s office.

How the Test Is Done

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and typically painless. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are interpreted in the context of your overall health, symptoms, and other tests. Abnormally high or low insulin levels can signal underlying conditions that require medical attention.

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

How long does it take to get my insulin test results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you once they are ready to review them with you.
Can I eat or drink before this test?
If fasting is required (e.g., for a glucose-insulin profile), avoid food and liquids—except water—8–12 hours before the test. If fasting isn’t needed, you can eat and drink normally. Follow your doctor’s instructions precisely.
Will I need to take any special steps after the test?
You may experience mild bruising or soreness at the injection site, which usually fades within a day. Apply gentle pressure to the area to help reduce swelling. If you experience excessive pain or signs of infection (e.g., redness, fever), contact your doctor.
  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