Benzodiazepines
A hair test that detects the presence and amount of benzodiazepine drugs in your hair, showing drug use over the past weeks to months.
Measures benzodiazepine levels in hair samples Can detect drug use over 1-3 months or longer Used to monitor medication compliance or detect drug abuse Hair testing is less affected by recent food or medication intake Results are reported as positive/negative or quantitative levels
Key facts at a glance
- LOINC
- 13933-7
- Short code
- BENZHAIR
- Synonyms
- Benzodiaz Hair-mCnt
- Category
- chemistry
- Sample
- serum
- Container
- Foil-wrapped hair specimen envelope or sterile specimen container; chain of custody container if forensic testing required
- Units
- N/A
- Ref low
- 0
- Ref high
- 0.01
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) or Gas Chromatography-Mass Spectrometry (GC-MS) following sample preparation and extraction
- CPT
- 80347 or G0480
- SNOMED
- 169480009
- Specimen volume
- 100-200 strands of hair (approximately 50-100 mg); proximal 3 cm segment of head hair preferred, cut close to scalp
- Stability
- Hair specimen stable indefinitely at room temperature in dry, dark conditions; stable for extended periods when stored in paper envelopes at ambient temperature
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 72–168 hours
- Order
- routine
What is this test?
This is a laboratory test that helps your healthcare team evaluate your health. Depending on the specific test ordered, it may involve a small blood sample, a urine sample, or another specimen collected at a clinic or laboratory, and the results provide your provider with important information about how your body is functioning.
The Benzodiazepines Hair Test is a laboratory test that measures the presence and concentration of benzodiazepine drugs in a hair sample. Benzodiazepines are a class of prescription medications commonly used to treat anxiety, insomnia, seizures, and muscle spasms. Examples include diazepam (Valium), alprazolam (Xanax), lorazepam (Ativan), and clonazepam (Klonopin).
How does it work?
Your sample is collected by a trained professional and sent to a laboratory, where specialized equipment and experienced staff analyze it. The lab measures specific substances or markers in your sample and reports the results to your provider, who then interprets them alongside your symptoms, medical history, and other findings.
When benzodiazepines are taken, they enter the bloodstream and tiny amounts become trapped in the hair follicles as hair grows. A small sample of hair (usually from the scalp) is collected and sent to a laboratory for analysis. The test can detect drug use over an extended period—typically the past 1-3 months, depending on hair length—making it useful for understanding long-term drug use patterns.
Why is this test ordered?
Doctors order this test to help diagnose a possible condition, monitor an ongoing illness, check how well a treatment is working, or screen for health problems before symptoms appear. Your provider may also include it as part of a routine checkup or use the results to guide decisions about your ongoing care plan.
Healthcare providers may order this test for several reasons: to monitor patient compliance with prescribed benzodiazepine therapy, to detect undisclosed or illicit benzodiazepine use, to evaluate patients with unexplained symptoms, or in forensic/legal settings. It may also be used in addiction treatment programs to verify abstention from benzodiazepines.
Reference range
Negative: <0.01 ng/mg (cutoff varies by laboratory). Positive findings interpreted based on clinical context; chronic benzodiazepine use typically yields concentrations >0.05 ng/mg depending on agent and frequency of use.N/A
No fasting required. Patients should be informed that chemical treatments (bleaching, perming, dyeing), cosmetic products, and environmental contamination may affect results. Hair should not be cut or chemically treated for at least 4-6 weeks prior to collection.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results indicate benzodiazepine use within the检测 period. The test can differentiate between different benzodiazepines, helping providers understand which specific drugs were used. Quantitative results (showing actual levels) may help distinguish between therapeutic use and overdose. In treatment settings, hair testing can help verify patient reports of medication adherence or abstinence. Negative results suggest no significant benzodiazepine use during the检测 window, though very occasional use might fall below detection thresholds.
Frequently asked questions
Does the test hurt?
Can hair products affect the results?
How long can benzodiazepines be detected in hair?
Will secondhand exposure cause a positive result?
Do I need to fast before this test?
Sources
- 1
- 2
- 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