Cannabinoid screening in serum/plasma
This test measures the presence of cannabinoids, the active compounds found in cannabis, in your blood. It helps detect recent or past use.
["Detects recent cannabis exposure for medical or legal purposes."]
Key facts at a glance
- LOINC
- 3425-6
- Short code
- CANNSR
- Synonyms
- Cannabinoids SerPl Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum collection tube (no anticoagulant) or serum separator tube (SST); alternatively, plasma may be collected in lavender-top (EDTA) or green-top (heparin) tubes
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay screening (e.g., EMIT, FPIA, or ELISA) with confirmation by Gas Chromatography-Mass Spectrometry (GC-MS) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 80307
- SNOMED
- 314529007
- Specimen volume
- 5-10 mL of whole blood yielding 2-4 mL of serum or plasma
- Stability
- Room temperature: 24 hours. Refrigerated (2-8°C): 7 days. Frozen (-20°C or lower): 6 months for THC-COOH stability. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 4–72 hours
- Order
- routine
What Does This Test Measure?
Cannabinoids are the psychoactive and non-psychoactive compounds in cannabis, including THC (tetrahydrocannabinol) and CBD (cannabidiol). This test typically screens for THC metabolites, which can linger in your system longer than the active compound itself. Results may indicate recent use or exposure to cannabis.
Why Might You Need This Test?
Your healthcare provider may order this test if you suspect recent cannabis use, for workplace drug screening, legal reasons, or to monitor substance use in a clinical setting. It’s also used in some medical contexts to assess exposure to cannabis-related compounds.
How Is the Test Performed?
A blood sample is drawn from a vein, usually in your arm. The serum or plasma is then analyzed using a sensitive laboratory method to detect cannabinoid metabolites. Results are reported as positive or negative for cannabinoid presence.
What Do the Results Mean?
A positive result means cannabinoid metabolites were detected in your blood, suggesting recent cannabis exposure. A negative result means no detectable cannabinoids were found. Interpretation depends on clinical context, such as timing of use or reason for testing.
Reference range
Negative: Cannabinoid concentration below the assay cutoff (typically 20 ng/mL for serum/plasma using SAMHSA-recommended screening thresholds). Positive results are reported when THC-COOH (11-nor-9-carboxy-Δ9-tetrahydrocannabinol) is detected at or above the cutoff concentration.N/A
No fasting required. Patients should be informed that cannabis use (including prescribed medical marijuana) will produce positive results. Avoid prescription and over-the-counter medications known to cause false-positive immunoassay results when possible. Specimen collection should follow chain-of-custody procedures for forensic or workplace testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance:
Short name
Cannabinoid test
Frequently asked questions
How long does it take to get results?
Can I drink alcohol before this test?
What if my results are positive?
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 15, 2026. · Read our editorial policy