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Insulin Concentration (Mass) in Serum or Plasma

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

This test measures the amount of insulin, a hormone produced by your pancreas, in your blood. It helps assess how well your body regulates blood sugar.

Quick summary

["Insulin levels help diagnose and monitor diabetes and other conditions affecting blood sugar."]

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

Key facts at a glance

LOINC
47665-5
Short code
Insulin 5M p Glc SerPl-aCnc
Synonyms
Insulin 5M p Glc SerPl-aCnc
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
2.6
Ref high
24.9
Fasting
true
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 this test to check for diabetes, insulin resistance, or other metabolic disorders. It’s also used to evaluate symptoms like unexplained weight loss, fatigue, or frequent urination. In some cases, it helps monitor treatment progress for conditions like hypoglycemia or hyperinsulinism.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before drawing blood. If you’re pregnant, have kidney disease, or take certain medications, let your doctor know beforehand.

How the Test Is Performed

A healthcare provider will insert a needle into a vein (usually in your arm) to draw blood. You may feel a small pinch, but the procedure is quick. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are interpreted based on your symptoms, medical history, and other test results. Abnormally high or low levels can signal underlying health issues that need further evaluation.

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 does fasting affect insulin test results?
Fasting for 8–12 hours before the test helps provide more accurate results by reducing fluctuations from recent meals. If you skip fasting, your insulin levels may appear artificially high or low, making it harder to diagnose conditions like diabetes.
Can insulin levels change with stress?
Yes, stress can temporarily raise insulin levels due to increased cortisol and other hormones. If stress is a concern, your doctor may recommend retesting after a period of calm or adjusting the timing of the test.
What if my insulin level is outside the typical range?
If your results are abnormal, your doctor will discuss them with you and may order additional tests or recommend lifestyle changes, such as diet or exercise adjustments, to better manage your health.
  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