The Health Trend That Might Give You a False Positive on a Drug Test

The world of drug testing is becoming surprisingly complicated. Medical marijuana is legal in 33 states, while recreational weed is legal in 10 states, but employers can still test employees (or potential hires) for marijuana use all across the country. Add cannabidiol (CBD) to the mix, and things get really confusing.

CBD, often ingested in oils, tinctures, and the occasional gummy bear, is really just a form of hemp- or marijuana-derived oil. It contains no psychoactive properties (so you don’t feel high), but there are growing studies showing CBD’s positive effects on anxiety, pain, and epilepsy in children. While CBD is totally legal, what are you supposed to do if you’re asked to take a drug screening? Will CBD show up on a drug test? Can you get fired for using CBD? I spoke to some experts to get some clarification on how CBD oil could potentially affect your test scores.

What exactly is CBD?

“Cannabis contains more than 100 different cannabinoids, with tetrahydrocannabinol (THC) and cannabidiol (CBD) being the most abundant,” says Mitchell Colbert, a cannabis researcher and journalist. THC is the stuff that makes you feel high, while CBD does not.

Regular weed comes from the cannabis plant, while CBD is derived from hemp. What’s the difference? “The legal definition of hemp is a cannabis plant that has less than .3 percent THC in it,” says Trista Okel, founder and CEO of CBD product retailer Empower Body Care. “That is the only legal differentiation between hemp and marijuana.” All pure CBD oil will have less than .3 percent THC but will be full of the (alleged) anxiety- and pain-reducing properties.

Do employers test for CBD?

“When an employer is doing a drug test for cannabis, they are looking for the presence of the intoxicating cannabinoid THC, not CBD,” Colbert says. Even in states where weed is legal, an employer can still choose to have a “drug-free” workplace and test to see if you’ve come across any THC lately.

“Drug screens are usually five-panel or 10-panel screens and test for other substances in addition to THC-COOH, which is what THC becomes after the body metabolizes it,” Okel says. Typically, you’ll be asked to produce a urine sample, it’ll go through screen tests for THC-COOH and other illegal substances, and you’ll find out if you passed.

Can you fail a drug test due to CBD?

Well, yes and no. “Most companies only search for the cannabinoid THC. That said, there are some testing facilities that check for a spectrum of cannabinoids, and therefore, THC-free CBD products could trigger a positive result,” says Sheri Kasper, RDN, LDN. “By law, you are allowed to ask the facility what cannabinoids they test for. If you are uncomfortable with that, you can call and ask anonymously.” These super-sensitive tests are rare, however. Most of the time, employers just want to know if you’re smoking weed all day, not if you’re taking CBD for your anxiety.

Still, CBD presents other risks for false positives. “If people are using CBD products that don’t have a CoA (Certificate of Analysis) that indicates zero THC, THC could show up on a drug screen,” Okel says. Availability of CBD oil has exploded, but it’s not a well-regulated industry. Some oils that claim to be pure CBD have some sneaky THC in there, and that could mess up a drug test. Okel advises everyone to only purchase CBD oils with CoA purity guarantee to avoid ingesting trace amounts of THC.

Again, CBD can legally contain up to .3 percent THC, so it’s possible (but not likely) that if you take a lot of CBD, the small amounts of THC could give you a false positive, Colbert says. One man claims he lost a job because of CBD oil, though it’s not clear if he’d taken an unusually large amount or if his oil contained some THC without his knowledge.

Make sure to read your labels. Some CBD oils openly contain higher doses of THC. Usually, you’d have to buy these from dispensaries, but you need to make sure you’re getting straight-up CBD if you’re not after any of the psychoactive effects or possible drug testing shenanigans.

Though this all sounds scary, it’s very unlikely that CBD oil will show up in a drug test. Just make sure that your CBD is sourced from a reputable retailer and you should be fine.

How long does CBD stay in your system?

Let’s say you took a CBD oil that had a bit of THC in it or you want to play it extra, extra safe before a drug screen. How long do you have to wait after your last CBD dose to take a drug test? “All cannabinoids are lipophilic,” says Glenn Harrison, M.D., an internist with a specialty in the use of cannabis in modern medical treatment. “They are actually forms of fat, so they get into the cells rapidly and will stay for a long time.”

It’s hard to say exactly how long CBD stays with you. It varies greatly depending on your size, BMI, and how often you’ve ingested CBD. “You cannot predict the exact amount of time that cannabinoids will appear in both urine and blood,” Harrison says.

Among all of the experts, there’s no hard and fast rule on how long it stays in your system. Again, if you’ve had pure CBD, it shouldn’t matter when you had it last since it won’t show up in urine tests. If you’ve had CBD and THC, the Colorado Pot Guide suggests you’ll be positive on a drug test within seven days of use. Now, if you take in a lot of THC, you could test positive for a month or more.

If you want to be extremely cautious, stop using CBD oil a month before a test. If you want to be mildly cautious, stop a week before. Since you’re not doing a specific CBD drug test, if you’re very careful that your CBD oil is THC free, then you should be able to take a general drug test the next day and be fine.

Is CBD legal?The 2018 Farm Bill removed hemp from the legal definition of marijuana in the Controlled Substances Act. This made some hemp-derived CBD products with less than 0.3% THC federally legal. However, CBD products containing more than 0.3% THC still fall under the legal definition of marijuana, making them federally illegal but legal under some state laws. Be sure to check state laws, especially when traveling. Also, keep in mind that the FDA has not approved nonprescription CBD products, and some products may be inaccurately labeled.

Amber Petty is an L.A.-based writer and a regular contributor to Greatist. Follow along as she shares her weight-loss journey in her new bi-monthly column, Slim Chance. You can also take singing lessons with Amber at Sing a Different Tune, check out her awesome podcast about The Masked Singer,and follow her on Instagram @ambernpetty.