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Insulin with 35-hour postprandial measurement (serum/plasma)

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

This test measures insulin levels in your blood taken after eating to assess how your body responds to glucose after a meal.

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
30261-2
Short code
Insulin 3.5h p chal SerPl-aCnc
Synonyms
Insulin 3.5h p 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

Why This Test Is Done

Your doctor may order this test if you have symptoms of diabetes or insulin resistance, or if you’re being monitored for conditions like prediabetes or metabolic syndrome. It can also help diagnose or manage certain endocrine disorders.

What to Expect Before the Test

You’ll typically fast for 8–12 hours before the test, but the sample is collected after a meal. Follow your doctor’s instructions precisely to ensure accurate results.

How the Test Works

A blood sample is drawn from a vein (usually in your arm) after you’ve eaten. The insulin level is measured using an immunoassay method to detect and quantify the hormone in your blood.

What the Results Mean

Results help determine if your body produces enough insulin after eating, which is important for managing blood sugar levels. Abnormal results may indicate issues like reactive hypoglycemia or diabetes.

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.

Clinical Significance

Short name

Insulin (35h post-meal)

Frequently asked questions

This test is particularly useful for diagnosing or monitoring conditions like **reactive hypoglycemia** (low blood sugar after eating) or **insulinoma** (a rare tumor producing excess insulin). It also supports evaluation of metabolic disorders affecting glucose metabolism.
This test is not typically part of routine screening unless symptoms or risk factors (e.g., obesity, family history of diabetes) suggest further evaluation is needed.
How often should I get this test?
Your doctor will decide the frequency based on your health status, symptoms, and treatment plan. Follow-up may occur annually or more often if managing a chronic condition like diabetes.
What if my results are outside the normal range?
If your insulin levels are unusually high or low, your doctor may recommend additional tests (e.g., glucose tolerance tests) or adjustments to your diet, exercise, or medication to better manage your 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