Sourced from SAMHSA & DOT · Medically reviewed · Updated 2026
Clear answers on drug & alcohol testing —
sourced, reviewed, and current.
A trusted reference for employers, parents, athletes, healthcare professionals, and individuals. Plain-language, primary-source citations, and a strict editorial rule: we don't publish content on defeating tests.
- Primary sources SAMHSA · 49 CFR Part 40 · ASAM
- Medically reviewed by AAMRO-certified MRO
- WCAG 2.2 AA — accessible to all readers
Who is this for?
Pick your starting point
Every audience has a different question — pick the one that fits and we'll route you to the right hub.
Test types
Five specimens, five different stories
Each specimen answers a different question — recent use, last few days, last few months. Start here to understand what each one actually tells you.
Urine
Detection~1–30 days (substance-dependent)
The federally approved gold standard for workplace screening.
Saliva
Detection~Hours to ~48 hours
Recent use detection; observed, non-invasive collection.
Hair
Detection~Up to 90 days (after ~7–10 day delay)
Up to ~90-day lookback; cannot show recent use.
Blood
Detection~Hours to ~1 day
Best evidence of recent use and active concentration.
Breath
Detection~Hours (alcohol only)
The federally approved method for alcohol testing.
Featured guides
Long-form references
Deeper, evergreen guides for decision-makers.
The complete guide to drug test detection windows
Substance-by-substance windows across urine, saliva, hair, blood, and breath — with caveats.
WorkplaceDrug testing for employers: a 2026 compliance overview
DOT vs non-DOT, panel choice, MRO process, state cannabis law — operator-grade guidance.
AccuracyUnderstanding false positives & cross-reactivity
Why immunoassay flags benign substances, and how confirmation testing rules them out.
How it worksScreening vs confirmation — immunoassay, GC-MS, LC-MS/MS
How two-step testing achieves both sensitivity and specificity. The 30-minute explainer.
How testing works
Collection → screen → confirm/MRO
Every defensible drug test follows the same three-step chain. Understanding it is the difference between reading a result and interpreting one.
- 01
Collection
A trained collector follows an unbroken chain of custody using a federal CCF for regulated tests. Urine, oral fluid, hair, or blood is collected to laboratory specification.
- 02
Screening
The specimen is screened using immunoassay. A "non-negative" screen is fast and sensitive — but not yet a positive. It triggers confirmation.
- 03
Confirmation & MRO
The lab confirms by GC-MS or LC-MS/MS. A licensed Medical Review Officer reviews the result and rules out legitimate medical explanations before reporting verified.
Why trust drugtest.co
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Quick answers
Frequently asked questions
It depends on the substance, the specimen tested (urine, saliva, hair, blood, or breath), and the person — dose, frequency, body composition, hydration, and lab cutoff all matter. Saliva typically shows recent use (hours), urine days, blood hours-to-days, and hair up to about 90 days. See our detection windows hub for substance-by-substance ranges.
The urine 5-panel is by far the most common in private-sector U.S. workplaces. DOT-regulated employers use the federally mandated DOT 5-panel under 49 CFR Part 40, which since July 7, 2025 also includes fentanyl and norfentanyl.
No. A positive workplace drug test confirms recent exposure (within the substance's detection window) but is not a measure of impairment, especially for cannabis where the urinary metabolite (THC-COOH) can persist days to weeks after any psychoactive effect ends. Refer impairment questions to a qualified Medical Review Officer.
For workplace and federally regulated testing, non-negative results are reviewed by a Medical Review Officer (MRO) — a licensed physician with specific training. The MRO contacts the donor to assess legitimate medical explanations before reporting a verified result to the employer.
SAMHSA's National Helpline (1-800-662-HELP / 4357) is a free, confidential, 24/7 information and treatment-referral service in English and Spanish for individuals and families facing substance use or mental health issues.
No. drugtest.co is an editorial reference site. We don't sell tests, collect specimens, or provide medical, legal, or HR advice. Our goal is plain-language, sourced information to help readers understand how testing works.
If you or someone you know needs help
SAMHSA National Helpline: 1-800-662-HELP (4357)
Free, confidential, 24/7 treatment referral and information service.
SAMHSA helpline →