CBD itself doesn’t get flagged on a drug test. But if you use cannabidiol products tainted with THC, you risk failing a drug test
The CBD craze has cooled significantly in the nearly three years since the federal 2018 Farm Bill legalized hemp cultivation nationwide, but products and supplements featuring cannabidiol—the non-intoxicating cannabinoid, legal in all 50 states—can still be found just about everywhere.
Oils and tinctures with CBD are available at health food stores and online, though providers are now much more careful with their sales pitches and steer away from marketing CBD products as miracle cures for people or pets. And though Delta-8 THC has taken a big bite out of the CBD market, CBD hemp flower is sold in bodegas and gas stations as well as smoke shops. And some adult-use cannabis dispensaries offer products featuring CBD.
Meanwhile, the true powers of CBD are still being discovered and there’s a lot of buzzy research: CBD may help solve cocaine addiction! Mixed with ketamine, CBD is an effective antidepressant, without negative side effects! (However, the studies are on mice in a lab, not humans.) Promising scientific discoveries are one reason why CBD products are popular with people who work in jobs where random drug tests are a part of their employment.
Can CBD Ruin a Drug Test?
As a 2019 study conducted by researchers at Johns Hopkins University found, CBD products may also trigger a failed drug test. How could this be, if CBD is not THC and not intoxicating—and how can you avoid it?
The trick here is to be sure that the CBD product you’re taking is in fact CBD—and only CBD. And sometimes, that certainty is hard to achieve.
What’s in a Drug Test?
Though drug testing as a prerequisite for employment is becoming less prevalent in the U.S. as adult-use cannabis legalization spreads to more states—a recent statistic from lab company Quest Diagnostics indicated that less than 1.5% of U.S. job postings advertise pre-employment drug screenings—certain employers and job sectors may still require a clean test.
These include public-safety professions and jobs where heavy machinery is operated, like trains, buses, forklifts and trucks. With severe shortages of long-haul truckers and Amazon always hiring, these are no small considerations.
Drug tests for cannabis may screen urine, blood, saliva, or hair follicles for evidence of cannabis metabolites, in particular a compound called delta-9-tetrahydrocannabinol carboxylic acid (THC-COOH). According to the Mayo Clinic, a drug test most likely will screen urine for evidence of THC-COOH, which can appear up to seven days after last use—or longer after heavy use.
“How much” will trigger a failed test depends on the tester’s cutoff level. If you’re trying to join the military or if you’re an active-duty servicemember, the Department of Defense’s threshold is 15 nanograms of THC metabolite per milliliter of urine. Other employers who comply with federal Drug Free Workplace Act requirements have a cutoff of 50 ng/ml.
What’s in Your CBD?
CBD by itself does not create the metabolite THC-COOH in the body.
In a study published in August in the journal Drug Testing and Analysis, researchers ran 259 saliva tests on 17 study participants who took between 15mg and 1,500mg of “pure CBD in a high-fat dietary supplement.”
And as the study authors reported: “THC, cannabinol and cannabigerol were not detected in any samples. … The likelihood of an individual who is using a CBD (only) oral formulation being falsely accused of [driving under the influence of cannabis] therefore appears low.”
Though pure CBD products like GW Pharmaceuticals’ Epidiolex are available by prescription, for now, other products advertised as containing CBD are not subject to any sort of quality-control regulation. As a result, many “CBD products” contain THC, sometimes at levels that can trigger a failed drug test.
And though scientists have discovered a method of drug testing that can differentiate between someone consuming a tainted batch of CBD versus regular cannabis, there’s no guarantee that the screening you’ll encounter is so sophisticated.
In other words: Buyer beware. When it comes to CBD, your drug test result will only be as good as the CBD product you’re using. CBD by itself will not ruin a drug test, but THC will—and many CBD products contain trace amounts (or more) of THC. Take the wrong product, or take too much of a mildly tainted product, and your risk increases.
If you’re not positive that the product is purely CBD and contains no THC, you may be unpleasantly surprised with a positive drug test.