Skip to content

Cotinine in Stool (24-hour collection)

Published: August 9, 2026Updated: August 17, 2026

This test measures cotinine, a breakdown product of nicotine, in your stool over a 24-hour period. It helps assess exposure to tobacco smoke.

Quick summary

["Cotinine in stool helps track nicotine exposure from smoking or secondhand smoke."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
59892-0
Short code
Cotinine Gast-sCnc
Synonyms
Cotinine Gast-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84484
SNOMED
302774002
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 healthcare provider may recommend this test if you suspect exposure to tobacco smoke, especially in children or individuals with respiratory issues. It can also be used in research or occupational health settings to monitor environmental nicotine exposure.

What to Expect Before the Test

You’ll need to collect a 24-hour stool sample in a special container provided by your lab. Follow the instructions carefully to ensure accurate results. Avoid certain medications that might affect nicotine metabolism.

How the Test Works

The collected stool sample is analyzed using a sensitive laboratory method (likely immunoassay or chromatography) to detect cotinine levels. This helps determine the amount of nicotine your body has processed over the past day.

What the Results Mean

Higher levels may indicate recent exposure to tobacco smoke, while lower levels suggest minimal or no exposure. Results are not used to diagnose smoking directly but are useful in research or specific clinical scenarios.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

What does a positive result mean?
A positive result (detectable cotinine) suggests recent exposure to nicotine, likely from tobacco smoke. This does not confirm smoking behavior but indicates environmental nicotine presence.
Can I stop taking medications before this test?
Yes, some medications (like certain antidepressants or nicotine replacement therapies) may affect cotinine levels. Ask your provider about potential interactions before the test.
How long does it take to get results?
Results typically arrive within 1–3 business days, depending on lab processing times. Follow-up with your healthcare provider if you have questions about interpretation.
  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 17, 2026. · Read our editorial policy