What Shows Up on a Hair Drug Test?
Hair drug testing is one of the most reliable ways to detect long-term drug use — but what exactly can it detect?
A longer window.
Hair tests detect drug use up to 90 days back, making them ideal for employers, families, and individuals seeking clarity over time.
Common substances detected:
- Marijuana (THC)
- Cocaine
- Opiates (heroin, morphine, codeine)
- Amphetamines (Adderall, methamphetamine)
- Benzodiazepines (Xanax, Valium)
- Methadone
- Ecstasy (MDMA)
- Barbiturates
- PCP
- Fentanyl (if included)
- Oxycodone
- Buprenorphine
Why fentanyl matters:
This potent opioid is increasingly mixed into street drugs without users’ knowledge. If you’re concerned about accidental exposure, look for tests that include fentanyl — not all do.
Accuracy:
Lab-processed hair tests are highly accurate, hard to cheat, and not impacted by shampoo or hair color.
Sources:
Quest Diagnostics. “Hair Drug Testing.” https://www.questdiagnostics.com/home/physicians/testing-services/by-test-name/hair-drug
American Addiction Centers. “Hair Drug Testing Facts.” https://americanaddictioncenters.org/rehab-guide/faq/hair-drug-tests
National Institute on Drug Abuse. “Fentanyl DrugFacts.” https://nida.nih.gov/publications/drugfacts/fentanyl