Does CBD show up on a drug test?

Medically reviewed by Ciera Cammilleri, PharmD

Blood testing is not an ideal way to detect THC (Shutterstock)

The short answer is no, CBD doesn’t show up on a drug test – because drug tests are looking for THC, not CBD. However, using full-spectrum CBD products can cause you to fail a drug test by testing positive for THC. ¹

How cannabis drug tests work

There are several different types of drug tests, all with varying levels of sensitivity and windows of detection.

Urine. Urine tests are a common method of drug testing both prior to and during employment, and are used for jobs of all levels. Detection of THC (and its metabolites) in urine can vary depending on dose and how frequently you consume, but a typical detection window is often about 3 – 15 days after last use. It can be even longer (30+ days) if you’re a heavy cannabis user. ²
Blood. Blood testing is not an ideal way to detect THC (and its metabolites). Because THC is metabolized and moved out the bloodstream, blood levels can be highly variable and have not been correlated with impairment. It is also quite invasive to have blood drawn, making this method less than ideal. These tests are typically used to try and prove impairment, since THC is only detectable in the plasma for a matter of hours after a single use, but its metabolites can be detected for up to seven days under the same conditions. ³ ⁴
Saliva. Saliva drug tests are less common in the US as THC or its metabolites can typically be detected in oral secretions for approximately 24-48 hours after last use. This time frame is longer for chronic users.
Hair. Hair testing is a more intensive type of drug testing, and is often used for vetting important positions like law enforcement or high risk jobs like truck driving. THC metabolites are detectable for a long time in hair – years even. Fortunately most standardized methods only use a few centimeters of hair closest to the scalp, resulting in detection for up to 90 days after light use.

What level of THC shows up on a drug test?

While private workplaces can set their drug testing requirements at their leisure, the Mayo Clinic established cutoff values for federal workplaces in 2017 to help minimize false-positive results from trace amounts of THC. So, technically you don’t need to have zero THC in your system in order to pass the test, you just need the amount of THC to be below the cutoff value. ⁵

Drug tests typically happen in two phases: screening and confirmation. These tests look for either THC or THC-COOH, a metabolite that comes from THC breaking down in your system.

Screening: the first phase typically uses an immunoassay test, where a sample of bodily fluid is analyzed for THC-COOH. The federal cutoff level for detectable THC metabolites in urine is 50 nanograms per milliliter. This test is fast and inexpensive, and as such is the most common type of drug tests. It is not as accurate as other test types, so it requires confirmation.

Confirmation: if your immunoassay test comes back positive, your drug test is sent to a lab for further confirmation, typically with a mass spectrometer– as laboratory device which can detect THC with much greater precision, most typically 15 nanograms per milliliter(ng/mL) of urine.

Hair and saliva tests can detect THC and THC-COOH at much lower levels. The typical cutoff for hair testing is 1 picogram per milligram, and 4 nanograms per milliliter for saliva. ⁶ ⁷

How to make sure your CBD product doesn’t contain THC

If you want to make sure you’re consuming CBD in a way that won’t make you test positive for THC on a drug test, you need to understand the difference in CBD products. There are three general types of CBD products on the market:

Full-spectrum. Full-spectrum products contain the full spectrum of chemical compounds in the hemp plant, including up to 0.3% THC as allowed by US federal law. This is why full-spectrum products can cause you to test positive, even with CBD products.
Broad-spectrum. Broad-spectrum products contain most of the chemical compounds in the hemp plant, excluding THC. Broad-spectrum products have been altered to remove any traces of THC, and should not cause you to test positive on a drug test – but always check the certificate of analysis (COA) to verify any marketing/labeling claims.
Isolate. CBD isolate is the CBD molecule alone, extracted and isolated from all the other compounds in the hemp plant. Isolate products should not cause you to fail a drug test.

These parameters work best when you’re buying products on the legal market, where you can access the certificate of analysis, the result from third-party lab testing, for your products. However, the CBD and hemp market is massive and mostly unregulated, so many products are inaccurately labeled. Some products contain far more CBD than labeled while others contain less. A 2017 study of the accuracy in online CBD products found only 30% of tested products were accurately labeled while 42% were under-labeled, and 26% were over-labeled. A whopping 21% contained THC, as high as ~6mg/mL, despite the fact that none were labeled as containing THC. ⁸

If you’re concerned about drug testing, always look for products that have a COA so you can verify what you’re consuming. These are not always 100% accurate, as testing can reflect a batch rather than your individual product, but it’s a good place to start.

Who has to take drug tests?

Many jobs use drug tests during the hiring process as a qualifying criterion. Some companies will randomly screen employees to ensure compliance with the company’s drug free workplace policy. Others will drug test after an accident to assess if the employee was impaired and is entitled to workers’ compensation. While drug tests are becoming less common in states with recreational cannabis, there are still many private, state, and federal positions that will not hire you if you test positive for THC.

Any military personnel
Truck and delivery drivers
Law enforcement
Aircraft pilots and other airport positions
Parolees
Healthcare professionals
Teachers

Problems with drug tests

The main problem with drug tests is that testing positive for THC doesn’t mean you’re high or that you were high recently. THC metabolites are fat soluble molecules, so they distribute to the fat cells in your body and linger there for up to three days after a single use and 30+ days after continued use. Other drugs can be undetectable in your body within hours, but cannabis can cause you to “test hot” long after you’ve consumed.

Drug tests can be unreliable, coming up with false positive results depending on the method of testing the submitted bodily fluid. Tests can also be evaded, falsified, or otherwise tampered with for a false result. ⁹

Additionally, drug tests are not morality tests, and testing positive for THC doesn’t inherently make you unable to do a job. While there are positions where being high would be dangerous and irresponsible, there’s no evidence to suggest that consuming cannabis during off time makes employees unable to work effectively.

Drug testing is especially problematic for people who consume cannabis medicinally. Patients shouldn’t be punished for using their medication, but at this time very states have medical protections for cannabis, even if it is recommended by a doctor.

Bottom line – does CBD show up?

CBD doesn’t show up on a drug test, but that’s because most drug tests aren’t looking for CBD. However, taking CBD can cause you to fail a drug test.

If you’re taking a CBD isolate or broad-spectrum product, you should be in the clear. But if you’re taking a full-spectrum product, be aware that it could cause you to test positive on a drug test and you may want to take a cannabis detox.

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