Cannabinoid Concentration in Blood (Screen)
This test measures the presence of cannabinoids, the active compounds found in cannabis, in your blood. It helps determine recent cannabis use.
["This test checks for recent cannabis exposure by detecting cannabinoids in your bloodstream."]
Key facts at a glance
- LOINC
- 42491-1
- Short code
- CANNB
- Synonyms
- Cannabinoids Bld Ql Scn
- Category
- chemistry
- Sample
- whole-blood
- Container
- Gray-top (sodium fluoride/potassium oxalate) blood collection tube; or lavender-top (EDTA) tube
- Units
- N/A
- Ref low
- 1
- Ref high
- 5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- screen
- CPT
- 80307
- SNOMED
- 251911007
- Specimen volume
- 5-10 mL of whole blood
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days for forensic chain-of-custody specimens
- Hemolysis max
- 100
- Lipemia max
- 150
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you’ve been suspected of using cannabis recently, if you’re under legal testing for substance use, or if symptoms like dizziness, altered mood, or impaired coordination are reported. It can also be used in workplace drug screens or legal investigations.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, typically drawn from a vein in your arm. The process takes a few minutes, and you may feel a slight pinch. Avoid cannabis use for at least 24 hours before testing if possible, as it may affect results.
What the Results Mean
Results indicate whether cannabinoids were detected in your blood. Positive results suggest recent cannabis exposure, but they don’t confirm the exact amount or duration of use. Levels can vary based on factors like metabolism, frequency of use, and how recently cannabis was consumed.
Common Uses and Limitations
This test is primarily used for screening, not confirming long-term use. It detects recent exposure within hours to days of consumption. Cannabinoids break down quickly, so levels may drop over time. False positives can occur if other substances are present or if the test is not recent.
Reference range
Negative (Cutoff: typically 1-5 ng/mL for THC-COOH depending on laboratory protocol)N/A
No special preparation required. Patient should be informed that results may be used for medical, legal, or employment purposes. Informed consent may be required depending on jurisdiction.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Cannabinoid Blood Screen
Frequently asked questions
What Does a Positive or Negative Result Indicate?
How Long Does It Take to Get Results?
Can Cannabis Use Affect Other Tests?
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