What Is Hair Drug Testing?
Hair drug testing is a laboratory-based test that uses a small hair specimen to identify patterns of drug use over a longer detection period than urine testing. It is commonly used for pre-employment screening, background verification, and non-DOT workplace programs.
Hair testing is not the standard DOT drug testing method for FMCSA drug testing, but it is useful for employers who want a broader look at prior substance use history under a non-DOT policy.
When Employers Use Hair Testing
Employers commonly use hair drug testing for pre-employment screening, executive or safety-sensitive role screening, return-to-work policies, internal workplace investigations, and employment programs where a longer detection window is important.
Hair testing may be especially useful for employers in construction, manufacturing, healthcare, staffing, logistics, and other environments where safety and reliability matter.
Hair vs Urine Drug Testing
Each test type has distinct strengths. Many employers use both - urine for DOT compliance and hair for pre-employment or policy-based screening.
Hair testing
- Up to 90-day detection window
- Identifies patterns of repeated use
- Harder to mask or substitute
- Not approved for DOT/FMCSA-regulated testing
- Best for pre-employment and background screening
Urine testing
- Detects recent use (days to roughly 30 days)
- Federally required for all DOT programs
- Faster results turnaround
- Required for RTD, random, and post-accident
- Best for DOT compliance and ongoing testing
Collection Process & Results
Hair samples are collected at certified collection sites by trained collectors. A sample of approximately 1.5 inches of head hair from close to the scalp is required, providing roughly a 90-day detection window. Body hair may be used as an alternative when head hair is unavailable, though the detection window may differ.
Roughly 1.5 inch head hair sample collected near scalp
Up to 90-day detection window
Sent to SAMHSA-certified laboratory for analysis
MRO review before results are released to employer
How It Works
1. Choose serviceSelect the DOT or non-DOT testing/compliance service you need.
2. Submit onlineComplete the order, enrollment, or request form with driver/employer details.
3. Use a nearby sitegoMDnow helps connect you with nationwide collection site access.
4. Stay compliantResults, documentation, and compliance support are handled according to the service type.
