Cannabinoid Screening in Urine (Qualitative)
This test detects the presence of cannabinoids, the active compounds found in marijuana, in your urine. It helps assess recent or past use.
["This urine test checks for marijuana use, often ordered for pre-employment, legal, or medical reasons."]
Key facts at a glance
- LOINC
- 91041-4
- Short code
- CANN
- Synonyms
- Cannabinoids Fld Ql Scn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum collection tube or serum separator tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- screen
- CPT
- G0434 (drug screen, other than chromatographic; any number of drug classes, qualitative)
- SNOMED
- 33500-4
- Specimen volume
- 5 mL of whole blood yielding approximately 2-3 mL of serum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test to determine if you’ve used marijuana recently. It’s commonly used in workplaces, schools, or for legal purposes where drug testing is required. It can also be part of a broader substance use evaluation.
What to Expect Before the Test
No special preparation is needed. You’ll provide a urine sample in a private setting. Avoid alcohol, certain medications, or dietary supplements that might interfere with results for 24–48 hours before testing.
What the Test Results Mean
A positive result means cannabinoids (like THC or its metabolites) were detected in your urine. A negative result means none were found. Results don’t indicate the amount or duration of use but confirm recent exposure.
Common Reasons for a Positive Result
Cannabinoids stay in the body for days to weeks, depending on use frequency and metabolism. Even light use can show up in urine tests for several days. Other factors, like hydration levels or certain medications, may also affect results.
Reference range
Negative (cutoff: typically 20 ng/mL or 50 ng/mL for THC-COOH depending on laboratory protocol)N/A
No fasting required. Patients should be advised that recent prescription or over-the-counter medications (e.g., dronabinol, nabilone, hemp-derived products such as CBD) may cause positive results. Informed consent may be required per institutional policy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Urine Cannabinoid Screen
Frequently asked questions
What does a positive result mean for my health?
How long will I need to wait before retesting?
Can I drink water before the test to dilute my urine?
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