Cannabinoid Screening in Urine (Mass Concentration)
This test checks for the presence of cannabinoids, the active compounds found in marijuana, in your urine. It helps determine if recent marijuana use occurred.
["This test screens for marijuana use and may be used for employment, legal, or medical reasons."]
Key facts at a glance
- LOINC
- 20413-1
- Short code
- CANN-U
- Synonyms
- Cannabinoids Ur Cfm-mCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, leak-proof urine collection container without preservatives; chain-of-custody container required for forensic or workplace testing
- Units
- N/A
- Ref high
- 15
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- confirm
- CPT
- 80349
- SNOMED
- 275916003
- Specimen volume
- Minimum 10-30 mL of urine; 50 mL preferred for confirmatory testing
- Stability
- Refrigerated (2-8°C): up to 7 days; Frozen (-20°C or below): up to 30 days for long-term storage. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you’ve been suspected of using marijuana recently, if you’re required for work or legal reasons, or if you’re part of a monitoring program (e.g., for substance use disorders). Some employers or schools use these results for hiring, promotions, or disciplinary actions.
What to Expect Before the Test
You’ll provide a urine sample in a sterile container. No special preparation is needed, but avoid drinking excessive fluids before giving the sample to ensure a proper volume. If you’ve recently used other substances (like alcohol or certain medications), inform your provider, as they may affect results.
What the Test Measures
The test detects cannabinoids, including THC (tetrahydrocannabinol) and its metabolites, which remain in your system for days to weeks after use. The mass concentration measures how much of these compounds are present in your urine.
Interpreting Your Results
Results are qualitative (positive or negative) rather than a specific quantity. A positive result means cannabinoids were detected, but it doesn’t specify the amount or duration of use. Follow-up testing (like a confirmatory assay) may be needed for legal or employment purposes.
Reference range
Negative: < cutoff concentration (typically 15 ng/mL for THC-COOH). Cutoff values vary by laboratory and regulatory guidelines.N/A
No special preparation required. Patient should be informed of test purpose. For workplace or legal testing, chain of custody collection protocol must be followed. Patients should disclose any prescription medications, over-the-counter drugs, or dietary supplements that may cause cross-reactivity.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Urine Cannabinoid Screen
Frequently asked questions
How long does it take to get results?
Can I drink water before the test?
What if I take certain medications?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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