People swear they were only using 100% cannabidiol (CBD), yet they failed their drug tests anyway. But urine screenings don’t check for CBD, so how can using this cannabis compound get you in trouble?

“CBD will not cause a false positive,” says Steven Dudley, PharmD, a clinical toxicologist and director of the Arizona Poison and Drug Information Center. “When people who use CBD products test positive for a cannabis or marijuana drug test, it’s linked to one thing: contamination with THC.” 

Many CBD companies tell you their products contain small amounts of tetrahydrocannabinol (THC), the active ingredient in marijuana that gets you high. But according to Dudley, mislabeling is a big problem. As a result, THC might be in so-called 100% CBD oil or other CBD products labeled as THC-free. In fact, that’s one reason CBD is not recommended if you are pregnant or breastfeeding. High doses have caused harm to developing fetuses in animal studies. The health effects of CBD in unborn human babies is not known. 

As CBD grows in popularity, experts warn that frequent use may affect workplace drug testing for marijuana use. And while there’s no guarantee you can use a CBD product and pass a drug test, “there’s something to be said for responsible use,” Dudley says. 

There are steps you can take to lessen your exposure to THC. But first, let’s dive into the sometimes confusing world of cannabis. 

What’s the Difference Between CBD, THC, Marijuana, and Hemp?

Cannabidiol (CBD) is a natural compound found in cannabis, including marijuana and hemp. There’s some evidence CBD may ease pain, anxiety, insomnia, and other health problems. But scientists are still researching the medical benefits of this cannabinoid.

Right now, there’s only one FDA-approved CBD drug. It’s a tightly controlled prescription medication used to treat rare types of seizures. But unregulated CBD products are widely available, from online sellers and local dispensaries to gas stations and grocery stores. 

Marijuana contains CBD, but most CBD products come from hemp. Legally speaking, hemp is any part of the cannabis plant with less than 0.3% delta-9 tetrahydrocannabinol (generally referred to as THC). But it’s not 0.0%, so there can be trace amounts of THC in many CBD products made from hemp.

High amounts of delta-9 THC can alter your mind and reflexes. But you can think of CBD more like you would an ibuprofen. 

“CBD is not psychoactive, and that’s its main selling point,” Dudley says. “And there is some evidence out there for its role in the inflammatory pathway and the pain process pathway, which is one of the main reasons people use it.”

How Can Using CBD Make You Fail a Drug Test? 

Companies sell CBD products with little to no THC. The problem is that you may not be able to trust that the ingredients listed on the packaging are what’s in the product. 

Studies show most CBD products sold online and in stores aren’t labeled accurately. While some have more or less CBD than advertised, what sets off alarm bells for experts is that some products contain THC even when labeled THC-free. 

You should note that even small amounts of legal THC can be a problem. While you’re unlikely to fail a drug test after a single use, you may be more likely to test positive if you use CBD products often (daily for weeks or months) or at high doses.

“Maybe the instructions say to use it one to three times a day, but they start using it six times a day,” says Matthew D. Krasowski, MD, PhD, chair of the College of American Pathologists Toxicology Committee. “Even though it’s not a huge amount of THC with each dose, it accumulates.”

Another thing to know is that urine drug tests check for THC metabolites – molecules that float around in the body after you break down a drug. A positive test shows that THC was in your body at some point. But it doesn’t say anything about how THC got there. 

But THC metabolites can build up over time and stick around in your body for quite a while. How long you test positive depends on how much and how often you use THC. Its metabolites commonly show up in urine tests for days to a week after a single exposure. 

If you use THC products often, “it’s definitely possible to test positive for 2 to 3 weeks,” Krasowski says. 

How To Avoid Failing a THC Drug Test While Using CBD 

Experts agree the safest choice is to stop using CBD products, at least close to your urine screening. Though not a guarantee, it’s a good idea to abstain for at least 30 days before your drug test.   

Other steps you can take include:

Try to buy THC-free products. Look for terms like broad-spectrum, THC-free, CBD isolate, or 100% CBD. Avoid anything labeled full-spectrum, which is more likely to have trace amounts of THC. Though, with product accuracy, “you’re really rolling the dice,” Dudley says. “Until there are forced regulations, you can’t be sure what you’re getting.”

Check for a certificate of analysis (COA). Verify that an accredited third-party lab tests the product you want to try. These labs analyze CBD products for high levels of THC and other cannabinoids and should have no link to the manufacturer. 

“The COA can be good, but it’s only reflecting what the manufacturer asks the testing laboratory to do,” Krasowski says. “And that can be misleading or presented in a way that’s not helpful to consumers. Whether that’s purposefully or sloppy is hard to say.”

Email the CBD company if you find the COA but don’t understand the results. 

Shop with a licensed dispensary. These folks may be more likely than non-licensed sellers to test the ingredients in their products and be honest with you about the results. Why? Because they run the risk of losing their license “and a ton of money” if they mislead customers, Dudley says. 

“I’m not saying there aren’t good manufacturers out there, but it certainly is the Wild West when you look at the CBD market overall,” he says. “And I think dispensaries are probably the ones who are doing the best job [regulating their products] because they have the most to lose.” 

Is Using CBD Worth the Risk?

Weigh the pros and cons of taking an unregulated supplement, and talk to your doctor about why you’re using CBD in the first place. They’ll help you find the best way to manage your medical conditions, which may include switching to more trusted treatments. 

And consider the consequences of a failed drug test. If you use CBD or want to in the future, ask yourself the following: 

  • Do you get drug tested regularly for work? 
  • Will you need to apply for a new job soon?
  • Do you have personal or secondhand exposure to marijuana? 
  • Are you pregnant and live in a state where newborns are tested for THC?
  • Are you on probation? Does your parole officer know you use CBD?
  • Will a positive THC test affect workers’ comp if you’re injured on the job?

If you use CBD and fail a drug test, there are ways to take a closer look at your results. For example, your employer (or parole officer) could order a follow-up lab test to measure the ratio of CBD to THC, which gives more info than a basic positive-negative urine drug screening. 

But urine tests are fast and cheap, and you may not get a second chance. “So, even though you can ‘prove your innocence’, you may unfairly face the consequences of a failed drug screen,” Dudley says. “Prevention really is the key.”