Hard Drug Screen
A laboratory screen checks a patient sample for selected controlled or illicit substances. The substances tested and whether confirmatory testing is needed depend on the laboratory.
["A positive screening result suggests possible drug exposure but may need confirmatory testing."]
Key facts at a glance
- LOINC
- 66981-2
- Short code
- Sold hard drugs nRate DYS
- Synonyms
- Sold hard drugs nRate DYS
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 140
- Ref high
- 280
- Critical range
- — – 1000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- denver-youth-survey
- CPT
- 83615
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
A hard drug screen is a laboratory test used to detect selected controlled or illicit substances in a patient sample. It is commonly used in substance-use assessment, workplace testing, and medical evaluation.
Why might I need this test?
This test may be ordered to evaluate possible drug exposure, monitor treatment or recovery, or meet an occupational or legal testing requirement. A clinician should interpret the result in the context of your symptoms, medications, and other findings.
How is the test performed?
The laboratory analyzes the submitted specimen using screening methods designed to identify selected drugs or their metabolites. A preliminary positive result is often followed by a more specific confirmatory test because screening tests can sometimes give misleading results.
How do I prepare for the test?
Follow the laboratory or clinician's instructions about the specimen and collection time. Tell the healthcare professional about all prescription medicines, over-the-counter products, supplements, and recent substance use, because these can affect interpretation.
Reference range
Adult: 140-280 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive screen may indicate recent exposure to one of the substances included in the panel, but it does not by itself establish when or how the substance was taken. False-positive and false-negative results are possible, so unexpected results should be confirmed with a specific laboratory method. A negative result cannot completely exclude exposure outside the detection period or to substances not included in the panel.
Short name
Drug screen
Frequently asked questions
Does a positive drug screen mean someone used drugs recently?
Can prescription medicines cause a positive result?
Does a negative result rule out all drug use?
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