Cocaine Hair Drug Screening (Mass Concentration)
This test measures the presence of cocaine in hair, providing a long-term view of substance use over weeks or months.
["Hair testing can detect past drug exposure, unlike blood or urine tests that show recent use."]
Key facts at a glance
- LOINC
- 27114-8
- Short code
- Cocaine Hair-mCnt
- Synonyms
- Cocaine Hair-mCnt
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
Why Hair Testing Matters for Cocaine Use
Hair follicles absorb substances like cocaine into the hair shaft over time, allowing for detection even after other tests (like urine) may no longer show evidence of use. This method is useful for monitoring long-term exposure or assessing historical substance use patterns, such as in employment screenings or legal cases.
How the Test Works
A small sample of hair is collected and analyzed using advanced techniques to detect cocaine metabolites. The concentration of cocaine in the hair reflects cumulative exposure over the months before testing, as hair grows slowly (about 0.5 inches per month).
What to Expect Before the Test
No special preparation is needed. You’ll provide a hair sample, typically a small section from the scalp or another part of the body. Avoiding hair dye or treatments that may interfere with results is recommended, but this is less critical than for urine or blood tests.
What the Results Mean
A positive result indicates detectable levels of cocaine metabolites in your hair, suggesting past use. However, the exact timing of exposure can be challenging to pinpoint without additional context (e.g., hair length). Negative results mean no detectable cocaine was found in the sample.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Hair testing for cocaine is valuable for detecting long-term substance use, which may not be captured by urine or blood tests. It’s commonly used in workplace drug testing, legal proceedings, or when monitoring chronic substance use patterns. However, it cannot distinguish between active use and historical exposure, so results should be interpreted alongside other clinical information.
Short name
Cocaine Hair Test
Frequently asked questions
Why might I need this test?
What does a positive result mean?
Can I stop using cocaine before the test, and will it affect results?
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