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Cotinine in Serum/Plasma (24-Hour Urine Screen Confirmation)

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

This test measures cotinine, a breakdown product of nicotine, to confirm recent exposure to tobacco smoke. It’s often used in follow-up after initial screening.

Quick summary

["Cotinine helps track nicotine use, supporting addiction treatment decisions."]

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

Key facts at a glance

LOINC
10365-5
Short code
Cotinine SerPl-mCnc
Synonyms
Cotinine SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is This Test Done?

Your healthcare provider may order this test if you’ve tested positive for nicotine in a screening test (like a saliva or urine sample) and need further confirmation. It helps ensure accuracy in detecting tobacco exposure, especially in cases where initial results might be borderline or unclear.

How Is the Test Performed?

A blood sample (serum or plasma) is collected, or a 24-hour urine sample is provided to measure cotinine levels. The test uses a sensitive method to detect even small amounts of cotinine, which can linger in the body after nicotine exposure.

What Does the Result Mean?

Results are qualitative (present or absent) rather than numeric. A positive result confirms recent tobacco exposure, while a negative result suggests no detectable nicotine breakdown product. This helps guide whether continued monitoring or treatment adjustments are needed.

Common Uses and Considerations

This test is typically used in addiction treatment to monitor progress, verify abstinence, or assess compliance with smoking cessation programs. It’s not a standalone test for diagnosing nicotine dependence but supports broader clinical decisions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Cotinine Confirmation

Frequently asked questions

What causes false positives or false negatives in this test?
False positives may occur if you’ve recently used other nicotine-containing products (e.g., vaping, nicotine patches) or if there’s a lab error. False negatives are less common but could happen if exposure was very recent or if the sample was improperly collected or stored.
How long does it take to get results?
Results are usually available within 1–3 business days, depending on lab processing times. Follow-up with your provider if you have questions about your specific result.
Can I stop taking nicotine products before this test?
Yes, it’s recommended to avoid all nicotine-containing products (including cigarettes, vaping, or nicotine patches) for at least 24 hours before testing to ensure accurate results. This helps avoid interference with the test.
  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