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Insulin, Serum/Plasma — Mass Concentration

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

A blood test that measures the amount of insulin in serum or plasma, helping assess how the body regulates blood glucose.

Quick summary

["This test measures insulin levels and can help evaluate symptoms of high or low blood sugar."]

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

Key facts at a glance

LOINC
1570-1
Short code
Insulin BS SerPl-mCnc
Synonyms
Insulin BS SerPl-mCnc
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

What is this test?

An insulin test measures the concentration of insulin, a hormone made by the pancreas, in a blood sample. Insulin helps glucose enter cells for energy and helps keep blood glucose levels within a healthy range.

Why might I need this test?

Your clinician may order this test to help evaluate unexplained high or low blood sugar, symptoms of excess or insufficient insulin, or how your body responds to food or glucose. It may be used in the assessment of diabetes, insulin resistance, or conditions affecting the pancreas.

How is the test performed?

A blood sample is collected from a vein and sent to a laboratory. The laboratory measures the amount of insulin present in the serum or plasma portion of the sample.

How do I prepare for the test?

Follow your clinician's instructions about eating, fasting, and the timing of the blood draw. Insulin results can be affected by recent meals, glucose levels, medications, and other factors, so tell the healthcare team about medicines you take and when the sample was collected.

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

Frequently asked questions

Does an insulin test require fasting?
Sometimes. Your clinician may request a fasting test or a test performed at a specific time in relation to a glucose-tolerance test. Follow the instructions provided for your specific order.
Why are insulin and glucose often tested together?
The results show how the body is handling glucose at the time of testing. Insulin and glucose together provide more context than either result alone.
Can medications affect the insulin result?
Yes. Insulin injections and medicines that affect glucose or insulin levels can influence the result. Tell the healthcare team about all medications and supplements you use.
  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