A standard drug test screens for marijuana, cocaine, opioids, amphetamines, and PCP. Those five categories make up the basic panel used for most employment and federal screenings, but each category covers multiple specific substances. Expanded panels can add benzodiazepines, barbiturates, alcohol markers, and more. What actually shows up depends on the type of panel ordered, the testing method used, and how recently a substance was consumed.
The Standard 5-Panel Test
The five-panel urine test is the most common drug screen in the United States. It’s the standard for all Department of Transportation workers, federal employees, and many private employers. Despite the name “5-panel,” it actually confirms 14 individual substances grouped into five categories:
- Marijuana (THC)
- Cocaine
- Opioids: codeine, morphine, heroin (detected as 6-AM), hydrocodone, hydromorphone, oxycodone, oxymorphone
- Amphetamines: amphetamine, methamphetamine, MDMA (ecstasy), MDA
- PCP (phencyclidine)
The opioid category was expanded in 2018 to include prescription painkillers like hydrocodone and oxycodone, which older tests often missed. This matters because these drugs are structurally different enough from morphine that they don’t trigger a standard opiate screening on their own.
Expanded Panels: 10, 12, and Beyond
Employers, courts, and treatment programs sometimes order broader panels. A 10-panel test typically adds benzodiazepines (like Xanax and Valium), barbiturates, methadone, propoxyphene, and methaqualone to the standard five. Some 12-panel tests also include buprenorphine and synthetic cannabinoids.
Fentanyl deserves special attention. Standard immunoassay screens historically missed it because its chemical structure is so different from morphine that it doesn’t trigger the usual opioid test. Detecting fentanyl requires a separate, fentanyl-specific test. The latest federal guidelines now include fentanyl as its own line item with an extremely low cutoff of just 1 ng/mL in urine, reflecting both its potency and its role in the overdose crisis.
How Cutoff Levels Work
Drug tests don’t simply detect “any trace” of a substance. Every test has a cutoff threshold, measured in nanograms per milliliter (ng/mL). If your sample falls below that number, the result is reported as negative, even if trace amounts are present.
For urine, the initial screening cutoff for marijuana is 50 ng/mL. If the screen comes back positive, a second confirmatory test checks at a lower threshold of 15 ng/mL. Cocaine’s initial cutoff is 150 ng/mL, amphetamines 500 ng/mL, and PCP 25 ng/mL. These thresholds are set by the Department of Health and Human Services specifically to reduce false positives from incidental or passive exposure.
Oral fluid tests use much lower cutoffs because drug concentrations in saliva are naturally lower. Marijuana’s initial oral fluid cutoff is just 4 ng/mL, and cocaine’s is 15 ng/mL.
Detection Windows by Testing Method
How long a substance stays detectable depends heavily on the type of test.
Urine testing is the most common method and offers a moderate detection window. Amphetamines and most opioids are detectable for 2 to 4 days. Cocaine typically shows up for 1 to 3 days. Marijuana has the widest range: an occasional user might test clean after a week, while a daily user can test positive for 30 days or longer after stopping. One documented case found cannabinoid metabolites in urine 102 days after the last use in a heavy, long-term consumer. THC is stored in fat tissue, which is why it lingers so much longer than water-soluble drugs.
Oral fluid (saliva) testing catches very recent use. Most substances are detectable for only 1 to 48 hours, making it useful for determining whether someone used a drug in the past day or two. As of late 2024, the DOT finalized rules allowing oral fluid collection as an alternative to urine for federal workplace testing.
Hair testing offers the longest detection window at up to 90 days for most substances. A standard hair sample is 1.5 inches, representing roughly three months of growth. Hair tests are poor at detecting very recent use (it takes about a week for drugs to appear in the hair shaft) but excel at showing patterns of use over time.
Delta-8, CBD, and THC Tests
Standard marijuana screens look for a specific metabolite of delta-9-THC, the psychoactive compound in cannabis. But delta-8-THC, which is sold legally in many states, breaks down into a very similar metabolite. Using delta-8 products carries a high risk of triggering a positive marijuana result on both the initial screen and the confirmatory test.
Pure CBD should not cause a positive result. In one study, every participant who used verified pure CBD (with no detectable delta-9-THC) tested negative. The catch is that many commercial CBD products contain small amounts of THC that may not be listed accurately on the label. About one-third of people using CBD products that contained detectable THC ended up testing positive for marijuana metabolites. If passing a drug test matters to you, the safest approach is to avoid all hemp-derived cannabinoid products entirely.
Alcohol on Drug Tests
Standard alcohol breath or blood tests only detect very recent drinking, typically within hours. But many programs now use EtG (ethyl glucuronide) testing, which looks for a byproduct your liver creates when processing alcohol. At the standard cutoff of 100 ng/mL, EtG can detect heavy drinking for up to five days and any drinking within the previous two days. At a higher cutoff of 500 ng/mL, it generally only picks up heavy drinking from the past day. EtG testing is common in court-ordered monitoring, probation, and substance abuse treatment programs.
Medications That Cause False Positives
The initial immunoassay screening is fast but imperfect. Certain common medications can trigger a false positive, which is why positive screens are always supposed to be confirmed with a more precise second test. Amphetamine false positives are the most frequently reported and can be caused by the antidepressant bupropion (Wellbutrin), the decongestant pseudoephedrine, and certain over-the-counter nasal inhalers.
Other known culprits include ibuprofen and naproxen (which have triggered false positives for marijuana), dextromethorphan in cough medicine (which can flag as PCP or opioids), the antihistamine diphenhydramine (Benadryl), the antidepressants sertraline and trazodone, and the heartburn medication ranitidine. The sleep aid doxylamine, found in NyQuil, has also been reported to cause false results.
If you take any of these medications and receive a positive initial screen, the confirmatory test should rule out the false positive. It’s worth mentioning your medications to whoever is administering the test, or to the medical review officer who interprets the results, before the process begins.