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Cannabinoid (THC and metabolites) screening in urine

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

This test detects the presence of THC (tetrahydrocannabinol) and its active metabolites in your urine, often used to screen for recent cannabis use.

Quick summary

["This test helps determine if cannabis use has occurred within the past few days to weeks."]

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

Key facts at a glance

LOINC
33282-5
Short code
Cannabinoids Mec Cfm-mCnt
Synonyms
Cannabinoids Mec Cfm-mCnt
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
confirm
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 order this test if you’re being evaluated for substance use, required for employment, legal reasons, or if you’re experiencing symptoms possibly linked to cannabis exposure. It can also be part of routine monitoring for chronic conditions where substance use is a concern.

How the Test Works

Urine is the preferred specimen because cannabinoids are stored in fat and slowly released into urine over time, providing a window into recent use.

What to Expect Before the Test

No special preparation is needed, but you may be asked to provide a urine sample in a sterile container. If you’ve recently used cannabis, results may be positive even if you’re not actively experiencing effects.

What the Results Mean

A positive result indicates the presence of cannabinoids, suggesting recent cannabis use. A negative result means no detectable cannabinoids were found in your sample. Interpretation depends on clinical context and timing of use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Cannabinoid Test

Frequently asked questions

How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on the lab’s processing time. Your provider will contact you once the results are ready.
Can I drink water before the test?
Yes, drinking water is fine before the test. However, avoid excessive fluid intake, as it may dilute the sample and affect accuracy. Follow any specific instructions your provider gives you.
What if my test is positive but I haven’t used cannabis recently?
A positive result could indicate residual cannabinoids from past use, especially if you’ve used cannabis in the weeks leading up to the test. If you suspect a false positive, discuss your medical history with your provider for further evaluation.
  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