The most common question we get from employers and families is some version of “should I do hair or urine?” The answer depends on what you need to know.
What each one measures
Urine reflects drug use over roughly the previous one to several days, longer for frequent use of some drugs. It is the right tool for “has this person used recently,” which is why it is the standard for post-accident, reasonable suspicion and most pre-employment programs.
Hair reflects use over roughly the previous three months for a standard head-hair sample, because drugs are incorporated into the hair shaft as it grows. It is the right tool for “has this person been using over time,” which is why it is common in high-trust hiring, custody matters and monitoring programs.
What each one misses
- Hair generally does not show use in the most recent week or so, because that hair has not grown out yet.
- Urine does not show a pattern; a single negative says little about last month.
- Neither measures impairment at the moment of collection.
When to use both
Some programs order both for the same person: urine for the recent window and hair for the history. That combination is common in pre-employment for sensitive roles and in court matters where a clean recent test and a longer clean history both matter.
Practical differences
| Urine | Hair | |
|---|---|---|
| Collection | Restroom needed; may be observed | Small lock cut near the scalp; no restroom |
| Adulteration risk | Higher; collection procedures address it | Low |
| Turnaround | Rapid screen on-site or lab in a few days | Lab only; a few business days |
| Starting price | $55 lab-based; $50 rapid | $100 standard; $300 segmented |
| DOT permitted | Yes | No |
The DOT rule
Hair testing is not DOT testing. DOT regulations authorize urine and oral fluid for drug tests, and because oral fluid is not yet available, DOT drug tests are currently urine collections. An employer with CDL drivers or other covered employees may use hair testing only as a separate Non-DOT company-policy test, on a non-federal form. It cannot replace the DOT test.
Segmented hair
If the question is not “did they use” but “when did they stop,” segmented hair testing analyzes the sample in sections to show a month-by-month pattern. It is ordered most often in family court and recovery monitoring. See segmented hair testing.
Both collections come to you. See hair follicle testing and lab-based Non-DOT testing, or call 1-800-539-4934 and describe the situation.