CBD, the non-psychoactive component of cannabis, has emerged on the scene as a natural remedy for a number of ailments, including anxiety, arthritis, and even special conditions of epilepsy. A growing number of people in my social circle and family have begun including CBD as a daily supplement for general wellness. I personally have found CBD to be useful in curbing my social anxiety and take CBD oil daily.

Since CBD comes from the same plant as THC, I began to wonder whether using it could lead to a failed drug test. With a drug test looming for a summer internship coming up, I wanted to be sure I could sleep easy knowing I was not risking my future job prospects or embarrassment in my current Doctoral program from having to tell my advisor that I failed a test. Additionally, since I have become a proponent of CBD myself, I want to be confident that I can suggest it to my friends knowing that I am not putting them at risk.

Whenever I ask my friends if they know whether it was possible to fail a drug test from using CBD, they do not seem too sure one way or another. Additionally, a quick google search revealed news stories across the country involving people who have gotten positive tests for the presence of THC even though they were only taking CBD supplements. This didn’t seem possible to me, so I decided to do a little more digging to try to understand the chances of failing a drug test due to taking CBD supplements.

In summary, what I learned was that the chances of testing positive for the presence of THC were very very low. In this article, I outline why this is the case.

First, there are two different varieties of cannabis plants: marijuana and hemp. The primary difference is that hemp contains nearly zero THC. THC is the psychoactive component of marijuana that will produce the ‘high effect.’ In fact, to classify as hemp, the strain must contain less than 0.3% THC. On the other hand, marijuana typically contains 5–35% THC. Since hemp doesn’t contain much THC, it can be produced and sold legally nationwide, whereas, marijuana is only legal in specific states. The passage of the Farm Bill in 2018, paved the way for the industrial-scale production of hemp, which has been a primary driver in the CBD boom.

However, there are a few ways that THC could get into your system from taking products labeled as CBD. Since the industry is not currently regulated by the Federal Drug Administration (FDA), it is not uncommon for the products to contain additional substances aside from pure CBD extract. In fact, one study discovered that almost 70 percent of the CBD products sold online were not labeled properly.

This most common reason for a failed drug test is due to consuming a low-quality CBD product that contains THC. One way this can happen is if the CBD is extracted from marijuana instead of hemp. Since marijuana contains more THC than hemp, there is the chance that the extract could contain more THC than advertised. Buying CBD from a dispensary in a state where THC is legal, as opposed to an online retailer, would increase your chances of encountering this problem.

One way to decrease your chances of having this happen is by learning the extraction method used to generate your particular product. This method determines whether the active CBD compound gets processed with other active compounds or cannabinoids. Full spectrum oil contains other compounds, whereas, pure CBD isolate does not. If you can confirm that your product was made with CBD isolate, you can ensure that you will not test positive for these substances.

Since the amount of THC is probably very low either way in your product, even if it is labeled improperly, you are still probably unlikely to trigger a false positive unless you are taking very large doses per day. For example, if you are consuming in upwards of 1,000 milligrams per day, it could trigger a false positive; however, the average CBD user typically only consumes between 120 to 160 milligrams daily.

Additionally, what makes this even more unlikely, is that most CBD products are not water-soluble. This drastically decreases the bioavailability of the product (aka the amount your body actually processes). So you may actually only get 10% of the CBD/THC that enters into your system. This is why some people add butter of something fatty to their coffees… it is to increase the bioavailability of the terpenes and other coffee compounds that often don’t get absorbed.

Still, Consumerlab president Tod Cooperman, whose company tests natural supplements like hemp-based CBD, warns that around 10 percent of those people who use CBD at this level can test positive for THC. So, “it can happen,” he said. “It also depends on not just the product, but some people metabolize CBD differently,” he added.

The fact of the matter is that drug tests are searching for the presence of the metabolites of THC in your body. THC and CBD will be metabolized into distinctly different chemical compounds. These metabolites are both fat-soluble, which means they bind to fat molecules in your body. As a result, it can take some time for them to leave your system. Simplified, unless you are consuming THC, you would not have the specific THC metabolites in your body that would trigger a positive result in a drug test. Additionally, the average drug test is not designed to pick up CBD, or any other compounds found in cannabis other than THC.

But what if my CBD product contains 0.3% THC as advertised? Would this be detected by a drug test? According to Brenda Gannon, a toxicologist and laboratory director at Steep Hill Arkansas, the answer is no. If your CBD has trace amounts of THC in it and you aren’t ‘chugging it by the bottle’ its metabolite, THC-COOH will probably not show up in drug test.

What bolsters this claim is the way in which drug tests are carried out in two phases. In phase one, the tester looks for the presence of THC-OOH. This test is sometimes susceptible to cross-contamination from other cannabinoids, thus giving the appearance that the levels of THC-COOH are higher than they really are. However, the second phase of the testing reveals the specific concentration of different compounds in the sample. By doing this, it ‘fingerprints’ the specific level of THC-COOH, and thus would confirm that the levels are actually lower than previously thought.

It is important to be aware of the type of drug testing you are going to undergo as well. Hair tests are designed to detect chronic use and are used to identify patterns of drug activity over the past 90 days. This is the longest detection window of detection for drug tests. Urine tests detection thresholds are even lower than hair tests and detect use over the past 10 or so days. The detection thresholds for a positive urine test are lower than for a hair test and thus are unlikely to pick up trace amounts of THC metabolites.

It is also important thing to be aware of is that the experimenter can also designate the sensitivity of the test, or the cutoff of THC-COOH that is considered a positive test. The most common cutoff for most urine tests is 50 ng/mL, but cutoffs can be as low as 15ng/mL and as high as 100ng/mL — each of which result in widely different detection windows.

For reference, a 1989 study of chronic users (~2 joints a day!) showed a maximum detection window of 25 days at a sensitivity of 20 ng/mL. Yet the study also pointed out that only one subject tested positive after 14 days, and it took an average of just 9.8 days before cannabinoid levels were no longer detectible. 8 out of the 10 subjects needed only 13 days to show their first negative result. Thus, if you want to be certain to not test positive, you can be pretty confident knowing that a relatively short hiatus from the CBD supplements can almost ensure that you will be fine.

One final take-home message that helped me feel confident going into my test was this. There is not a standard test for CBD at the moment. Given that CBD is a distinctly different chemical compound than THC, a specific test would have to be commissioned and paid for, which would require notifying the testing company and potential employee that the employer is testing for an additional substance, paying the company a charge for the additional test, and purchasing additional standards. They would also have to modify their operating procedures to include CBD. Since CBD doesn’t get you high and impair your job functions, it is unlikely a company would spend extra money and time to try and detect it. In fact, one of the biggest drug testing companies in the United States, Quest Diagnostics, does not even offer testing for CBD.

Thanks for reading!

-J