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Insulin, Prechallenge — Serum/Plasma, Analyte Concentration

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

Measures insulin in serum or plasma before a challenge, most often a glucose tolerance test, to help assess insulin secretion and blood sugar control.

Quick summary

["Prechallenge insulin helps clinicians evaluate how effectively the body produces and uses insulin."]

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

Key facts at a glance

LOINC
49897-2
Short code
Insulin pre chal SerPl-aCnc
Synonyms
Insulin pre 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

What is this test?

This test measures the amount of insulin in a blood sample before a challenge, such as a glucose drink. Insulin is a hormone made by the pancreas that helps glucose enter cells for energy.

Why might I need this test?

It may be ordered with a glucose tolerance test to evaluate insulin secretion and how the body handles a glucose load. It can also help investigate symptoms or conditions involving low or high blood sugar.

How is the test performed?

A blood sample is collected from a vein before the challenge is given. The laboratory measures the insulin concentration using a validated laboratory method, and the result is interpreted along with glucose and other test findings.

How do I prepare for the test?

If this is part of a glucose tolerance test, you may need to fast for the period specified by your clinician, often overnight. Follow all instructions about food, drinks, and medications, and tell the testing team about any diabetes medicines you take.

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

Prechallenge insulin

Frequently asked questions

Is fasting required for a prechallenge insulin test?
It depends on the testing protocol. When it is part of a glucose tolerance test, fasting is commonly required for the period specified by your clinician.
How is this test different from a routine insulin level?
A prechallenge insulin result is specifically timed before a challenge, often a glucose drink. A routine insulin test may be drawn without a challenge, so timing and interpretation can differ.
Does one abnormal insulin result diagnose diabetes?
No. The result must be considered with glucose levels, symptoms, medical history, and other laboratory findings. Your clinician can explain what the result means in your situation.
  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