Cannabinoid Mass Concentration in Urine (24-Hour Collection)
This test measures the presence of cannabinoids, the active compounds found in marijuana, in your urine over a 24-hour period. It helps detect recent use of cannabis.
["Detects recent marijuana use in your urine over a full day."]
Key facts at a glance
- LOINC
- 33561-2
- Short code
- CANNGF
- Synonyms
- Cannabinoids Gast-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof plastic container (no preservative); red-top tube acceptable if serum is used
- Units
- N/A
- Ref low
- 0
- Ref high
- 10
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Gas Chromatography-Mass Spectrometry (GC-MS) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 80307
- SNOMED
- 395112001
- Specimen volume
- 5-10 mL of gastric fluid
- Stability
- Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days; Room temperature: 24 hours
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if they suspect recent marijuana use due to symptoms like altered mood, sleep changes, or if you’re involved in a workplace drug screening, legal proceeding, or medical evaluation requiring substance monitoring.
What to Expect Before the Test
You’ll collect a 24-hour urine sample starting from the time you wake up until the next morning. Follow your doctor’s instructions carefully to ensure accurate results. Avoid certain medications or substances that could interfere with the test.
What Happens During the Test
Your sample is analyzed in a lab using a specialized method to measure cannabinoid levels. The lab will check for the presence of THC (tetrahydrocannabinol) and its metabolites, which are detectable in urine for days after use.
What the Results Mean
Positive results indicate recent marijuana use. Negative results mean no detectable cannabinoids were found in your sample. Consult your healthcare provider for interpretation based on your specific situation.
Reference range
Negative: <10 ng/mL (typical cutoff for cannabinoids in gastric fluid). Positive results should be interpreted in clinical context.N/A
No special patient preparation required. Specimen is typically collected via gastric lavage or nasogastric tube in suspected overdose or poisoning cases.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test is primarily used for screening purposes to identify recent cannabis exposure. It can be part of broader substance use assessments, workplace compliance checks, or legal evaluations. Results should always be discussed with your provider to understand implications for your health or situation.
Short name
Urine Cannabinoid Screen
Frequently asked questions
How long can marijuana be detected in urine?
What if I take certain medications or supplements?
Can I drink alcohol before this test?
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 17, 2026. · Read our editorial policy