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Insulin, Serum Concentration

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

This test measures the amount of insulin in your blood serum, which helps assess how your body produces and uses insulin for energy.

Quick summary

["Insulin levels help diagnose conditions like diabetes or check how well your treatment is working."]

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

Key facts at a glance

LOINC
56546-5
Short code
Insulin Ab Ser IA-aCnc
Synonyms
Insulin Ab Ser IA-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
Method
ia
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, monitor blood sugar control, evaluate insulin resistance, or investigate unexplained symptoms like fatigue, weight changes, or unusual thirst/urination.

What to Expect Before the Test

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

How the Test Works

A blood sample is drawn from a vein (usually in your arm). The sample is sent to a lab where insulin levels are measured using an immunoassay method to detect the hormone.

What the Results Mean

Results help determine if insulin production is normal, low, or high. Abnormal levels may indicate diabetes, insulinoma, or other metabolic disorders.

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.

High insulin levels can signal insulin resistance, hypoglycemia (low blood sugar), or tumors producing excess insulin. Low levels may suggest diabetes, pancreatic issues, or poor insulin secretion.

Short name

Serum Insulin

Frequently asked questions

What causes abnormal insulin levels?
Abnormal insulin levels can result from conditions like diabetes, pancreatic tumors, thyroid disorders, or medications that affect blood sugar. Lifestyle factors (e.g., diet, exercise) also play a role.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time.
Can I eat or drink before this test?
If fasting is required, avoid food and liquids (except water) for 8–12 hours before testing. Check with your doctor for specific instructions.
  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