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Insulin, Serum or Plasma Concentration (Quantitative)

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

This test measures the amount of insulin in your blood, which helps regulate blood sugar levels. Insulin is a hormone produced by your pancreas.

Quick summary

["Insulin levels help diagnose conditions like diabetes and check how well your body manages blood sugar."]

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

Key facts at a glance

LOINC
47655-6
Short code
Insulin 15M p Gc SerPl-aCnc
Synonyms
Insulin 15M p Gc 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 Is This Test Done?

Your doctor may order this test to check for diabetes or other blood sugar issues, evaluate how your body responds to insulin, or monitor existing diabetes treatment. It can also help diagnose conditions like hypoglycemia (low blood sugar) 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 fasting study. Bring any medications you’re taking to your appointment.

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 it’s usually over quickly. The blood sample is sent to a lab for analysis.

What the Results Mean

Results help determine if your insulin levels are too high, too low, or within a normal range. Abnormal results may indicate diabetes, insulin-related disorders, or other metabolic conditions.

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 long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
If fasting is required (e.g., for a glucose study), avoid food and liquids except water for 8–12 hours before testing. If no fasting is needed, you can eat and drink normally.
What does an abnormal insulin level mean?
Abnormally high insulin levels may signal conditions like insulinoma (a rare tumor) or reactive hypoglycemia, while low levels could indicate diabetes or pancreatic issues. Your doctor will interpret results in the context of your overall 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