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Insulin concentration (serum/plasma) measured 1 hour post-glucose challenge

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

This test measures your insulin levels one hour after drinking a glucose solution to help assess how your body responds to sugar.

Quick summary

["Helps evaluate how well your pancreas produces insulin after eating."]

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

Key facts at a glance

LOINC
55488-1
Short code
Insulin 1h p Gc SerPl-sCnc
Synonyms
Insulin 1h p Gc SerPl-sCnc
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 Is Done

Your doctor may order this test if they suspect you have diabetes, prediabetes, or an issue with how your body processes glucose. It’s often part of a glucose tolerance test, which checks how your body handles sugar over time.

What to Expect Before the Test

You’ll drink a sweet liquid (glucose solution) while fasting. Blood is drawn from a vein (usually in your arm) before and one hour after drinking it to check insulin levels. No special preparation is needed beyond fasting for 8–12 hours before the test.

What the Results Mean

Results help determine if your body produces enough insulin after eating. Abnormal results may indicate conditions like diabetes, insulin resistance, or other metabolic disorders. Your doctor will discuss findings with you.

Common Conditions Linked to This Test

This test is critical for diagnosing or monitoring diabetes, gestational diabetes, or conditions affecting insulin production (e.g., pancreatitis, pancreatic tumors). It may also help assess rare genetic disorders like maturity-onset diabetes of the young.

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

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 1–3 business days, depending on your lab. Your doctor will contact you once they’re ready.
Can I eat or drink anything before this test?
No, you must fast for 8–12 hours before the test. Avoid food, drink (except water), and smoking.
Is the blood draw painful?
The needle used for drawing blood is small and inserted quickly. Most people feel only a brief pinch. You may have a small bruise afterward, but it’s usually mild discomfort.
  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