Marijuana (THC) Drug Test
Updated October 14, 2026
THC is the active compound in cannabis (marijuana), including smoked, vaped, and edible forms.
The Marijuana (THC) panel is one of the 14 on every Testr urine drug test, read on site by a certified collector at your door anywhere in the Los Angeles area. On a Testr report it is printed as THC (Cannabis / Marijuana).
How long does THC stay in your system?
That range is typical rather than a guarantee: how much was taken, how often, body weight and hydration all move it.
The screening cutoff above is the level at or above which the on-site cassette reads positive. Below it the panel reads negative even when a trace is present, which is why the cutoff matters as much as the number of days.
Can a prescription cause a positive on the Marijuana (THC) panel?
Some legal CBD products contain enough THC to cause a positive result.
What does a positive on the Marijuana (THC) drug test panel mean?
The on-site read is a drug screen. It reports positive or negative against the screening cutoff, not a measured level. Laboratory confirmation is what produces a number: a CAP-accredited laboratory quantifies the specimen by LC-MS/MS and reports measured levels, in about 72 hours. Every laboratory report goes to a Medical Review Officer (MRO), a physician who reviews laboratory-confirmed results and accounts for valid prescriptions before the report is released. Confirmation can be added when you book, or from the app within 2 hours of collection, while the specimen is still viable.
Smoked, vaped, edible or delta-8: what the THC panel reads
Every form of cannabis ends up as the same thing in urine. Smoked flower, vape cartridges, edibles, tinctures and dabs all deliver THC, and the body breaks THC down into THC-COOH, the metabolite the THC panel screens for at 50 ng/mL. The form does not change what the strip looks for.
Delta-8 and other hemp-derived THC products produce THC-COOH too and can read positive. Synthetic cannabinoids sold as K2 or Spice do not, and do not react on this strip; whether they show up at all is covered on the K2 and Spice drug test page.
Why the THC window runs from days to weeks
THC is stored in body fat and released slowly, which is why this panel has the widest window on the cassette: THC is detectable for about 3 days after occasional use, but up to 30 days or more with heavy daily use. A single occasional use and months of daily use sit at opposite ends of that range, and the cutoff decides where a given specimen falls. Other cups print THC with different cutoffs, so one specimen can read differently on two cups; on a Testr screen the cutoff is 50 ng/mL.
Prescription THC and the laboratory
Dronabinol, sold as Marinol and Syndros, is a prescription form of THC and reads on this panel like cannabis. CBD itself is not what the strip looks for; the concern with CBD products is the THC some of them carry. Laboratory confirmation measures THC-COOH at 10 ng/mL, a fifth of the screening cutoff, and reports the level. Whether legal or medical cannabis use matters for a particular job is a question for employment counsel, not something a test result answers.
What a THC line cannot tell you
A positive THC line says THC-COOH reached 50 ng/mL in the specimen. Because that metabolite can stay detectable for up to 30 days or more after heavy daily use, a positive cannot show when cannabis was last used, whether anyone was impaired, or which product it came from. After occasional use it is detectable for about 3 days. Laboratory confirmation adds a measured level; it does not add a time of use.
What THC means on the report
What does THC mean on a drug test?
THC stands for tetrahydrocannabinol, the active compound in cannabis. On a Testr report, and on most test cups, this panel is printed as THC. On a Testr screen the THC panel reads positive at or above 50 ng/mL, and it is detectable for about 3 days after occasional use, but up to 30 days or more with heavy daily use.
What is the THC cutoff on a drug test?
50 ng/mL on a Testr screen: at or above that level the THC panel reads positive, below it negative. Other cups can print THC with a different cutoff. Laboratory confirmation applies its own cutoff to each compound it measures and reports the measured level rather than a positive or negative.
Every code on the cassette, with its cutoff and detection window, is on one page: drug test abbreviations, decoded.
More questions about Marijuana (THC)
Does delta-8 show up on a drug test?
It can. Delta-8 and other hemp-derived THC products produce THC-COOH, the same metabolite the THC panel screens for at 50 ng/mL, so they can read positive.
Do edibles show up differently from smoking?
Not on the strip. Edibles, vapes and smoked cannabis all produce THC-COOH, which the THC panel reads against the same 50 ng/mL cutoff; THC is detectable for about 3 days after occasional use, but up to 30 days or more with heavy daily use.
Does Marinol show up as THC?
Yes. Marinol and Syndros contain dronabinol, a prescription form of THC, so they produce THC-COOH and can read on the THC panel. Laboratory confirmation measures THC-COOH and reports the level.
Does CBD oil show up on a drug test?
The THC panel does not look for CBD. Some products sold as CBD contain enough THC to cause a positive, and that is THC actually present, not a reaction to the CBD.
How the Testr drug test screens for it
This panel is part of every Testr drug test. A certified collector handles the urine collection at your home, checks specimen temperature, and reads a clinical 14-panel drug screen cassette on the spot. For measured levels rather than a positive/negative read, add laboratory confirmation: a CAP-accredited lab quantifies the result by LC-MS/MS, with measured levels on the report. Testr covers the Los Angeles area seven days a week, 7 AM to 7 PM, with the earliest window 3 hours after you book.