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Insulin, Serum Concentration (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. It helps assess how well your body regulates blood sugar.

Quick summary

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

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

Key facts at a glance

LOINC
27444-9
Short code
Insulin 40M p chal SerPl-aCnc
Synonyms
Insulin 40M 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 This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms of low blood sugar (hypoglycemia), such as shakiness, dizziness, or sweating. It may also be used to evaluate insulin production in people with diabetes or suspected insulinoma (a rare tumor that causes excessive insulin production).

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 study. Bring any medications you’re taking to your appointment.

How the Test Is Performed

A blood sample is drawn from a vein, typically in your arm, using a small needle. You may feel a brief pinch, but the procedure is quick. The sample is sent to a lab for analysis using an immunoassay method to measure insulin concentration.

What the Results Mean

Results are reported in units of mass concentration (e.g., micrograms per liter). Interpretation depends on clinical context, such as symptoms, other test results, and medical history. Abnormally high or low levels may indicate underlying conditions requiring 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

Serum Insulin

Frequently asked questions

What causes insulin levels to be unusually high?
Unusually high insulin levels can result from conditions like insulinoma (a rare tumor), reactive hypoglycemia (a temporary drop in blood sugar), or certain medications. It may also occur in people with diabetes who are taking insulin or other glucose-lowering drugs. If you’ve had unexplained symptoms or recent changes in medication, mention them to your doctor.
What symptoms might indicate abnormal insulin levels?
Symptoms of high insulin levels (hyperinsulinemia) may include unexplained weight gain, fatigue, or shakiness. Symptoms of low insulin levels (hypoglycemia) can include dizziness, confusion, sweating, or rapid heartbeat. If you experience these symptoms, talk to your healthcare provider about further testing.
How often should I get this test?
The frequency of this test depends on your health condition. People with diabetes may need regular monitoring, while others might only need it if symptoms or risk factors (like family history) suggest it’s necessary. Follow your doctor’s recommendations for timing and repeat testing.
  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