Cannabinoid screening (qualitative) in serum/plasma
This test detects the presence of cannabinoids, the active compounds found in marijuana or cannabis, in your blood or plasma.
["This screening helps identify recent cannabis use, which may affect your health or medical treatment decisions."]
Key facts at a glance
- LOINC
- 48943-5
- Short code
- CANCO
- Synonyms
- Cannabinoids Spec Ql Cfm
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (no anticoagulant) or serum separator tube (SST); sterile urine container for urine specimens. For forensic testing, use chain-of-custody containers.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- confirm
- CPT
- 80349
- SNOMED
- 314529007
- Specimen volume
- 5-10 mL of blood (minimum 3 mL serum) for serum testing
- Stability
- Serum stable at room temperature for up to 24 hours; refrigerated (2-8°C) for up to 7 days; frozen (-20°C or below) for up to 3 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you’ve been suspected of using cannabis recently, if you’re under legal testing (e.g., workplace, legal proceedings), or if symptoms like altered mood, memory issues, or physical coordination problems are reported.
What Does the Test Measure?
The test looks for specific cannabinoids, including THC (tetrahydrocannabinol) and its metabolites, which are detectable in blood/plasma for a short period after use.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate plasma (the liquid part) for testing. This test is typically done as part of a routine or urgent evaluation.
What Are Common Reasons for Testing?
Common reasons include confirming recent cannabis use for legal, occupational, or medical reasons, assessing symptoms that may be linked to cannabis exposure, or evaluating substance use patterns in clinical settings.
Reference range
Negative (not detected). Cutoff concentration for positive confirmation varies by laboratory and regulatory guidelines; typically ≥1 ng/mL for THC-COOH in serum.N/A
No fasting required. Specimen should be collected prior to administration of medications or substances when possible. Chain of custody documentation is required for forensic or workplace drug testing. Patient should be informed of testing purpose and consent obtained where applicable.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results may indicate recent cannabis use and could influence treatment plans, especially if you’re taking medications that interact with cannabinoids or if symptoms suggest impairment. However, results alone should not be used to diagnose a substance use disorder without further evaluation.
Short name
Cannabinoid Screen (Serum/Plasma)
Frequently asked questions
How Long Does It Take to Get Results?
What If My Results Are Positive?
Can I Avoid 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 15, 2026. · Read our editorial policy