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24-Hour Urinary C-Peptide Excretion Rate

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

This test measures how much C-peptide your body releases into your urine over 24 hours. C-peptide is a natural substance produced along with insulin during digestion, helping doctors assess how well your pancreas is making insulin.

Quick summary

["This test helps evaluate pancreatic function and insulin production over time."]

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

Key facts at a glance

LOINC
27944-8
Short code
C peptide 24h Ur-mRate
Synonyms
C peptide 24h Ur-mRate
Category
coagulation
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85610
SNOMED
396252006
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if they suspect conditions like diabetes, pancreatic disease, or other metabolic disorders that affect insulin production. It can also help monitor long-term pancreatic health or rule out certain genetic or autoimmune conditions.

What to Expect Before the Test

No special preparation is needed. You’ll provide a 24-hour urine sample collected in a container, starting after your first morning urine void and continuing until the next morning. Drink plenty of fluids to help urine flow normally.

How the Test Works

Your urine is tested for C-peptide, a marker of insulin production. The rate measures how much C-peptide is excreted, reflecting how much insulin your body naturally produces and releases.

What the Results Mean

Results are compared to a baseline or clinical reference range provided by your healthcare team. Abnormal results may indicate insufficient insulin production, pancreatic issues, or other metabolic imbalances.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: urine

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

C-Peptide Urine Rate

Frequently asked questions

What does a high or low C-peptide urine rate mean?
A high rate may suggest overproduction of insulin (e.g., in some pancreatic tumors or rare genetic disorders), while a low rate could indicate insufficient insulin production (e.g., diabetes, pancreatic damage). Your doctor will interpret results in context with your symptoms and other tests.
Can diet or medications affect this test?
Dietary changes or medications that alter insulin levels (e.g., diabetes medications, steroids) may influence results. Always inform your doctor about all medications or supplements you’re taking.
Is this test painful or uncomfortable?
No, this test is not painful. You simply collect urine over 24 hours in a container, similar to a standard urine sample. Most people find it convenient to use a timer or reminder to ensure full collection.
  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