I. Technically, CBD shouldn’t trigger a positive drug test...

Because THC is the chemical that makes people intoxicated, that is what a drug test screens for, not CBD.

Currently, only CBD oil derived from hemp plants is legal in the U.S., based on the fact that hemp contains less than 0.3 percent THC. By law, CBD oil made from hemp cannot contain more than 0.3 percent THC (although pure CBD should not contain any THC at all).

Marijuana, which also produces CBD, contains more than 0.3 percent THC, making it illegal according to federal guidelines.

Theoretically, if you use CBD oil derived from hemp plants, it should be free of THC. Without THC in your system, you will pass a drug test screening for marijuana use.

II. ...but in some cases, it can.

Just because it’s not likely that using CBD oil will cause you to test positive for THC on a drug test, doesn’t mean that it’s impossible. CBD oil can contain trace amounts of THC. If enough THC accumulates in your system, it will trigger a positive result in a drug screening.

The reason for possible impurities in CBD oil is the fact that the industry is largely unregulated. The Food and Drug Administration (FDA) does not evaluate CBD products to ensure that they only contain the ingredients listed on the label in the proper amounts. This can lead to situations in which hemp-derived CBD oils with more than the legal amount of THC reach consumers.

There are a few reasons that the purity of CBD oil can be compromised by the presence of THC:

  • Mislabeling. Because CBD products fall outside the purview of the FDA, labels listing ingredients, amounts, and other product information are not subject to an objective evaluation for accuracy. Therefore, it’s possible that products are mislabeled, intentionally or unintentionally, and contain trace amounts of THC even when the label says they do not. In 2017, an independent study found that 18 out of 84 samples contained THC, and there have been other anecdotal incidences of CBD products containing THC, even when their labels said otherwise.
  • CBD is derived from marijuana. As mentioned previously, CBD is present in both marijuana and hemp plants. If you are using CBD oil derived from marijuana plants, it is more likely that the oil will contain THC, even if THC is not specifically listed as an ingredient on the label.
  • Cross-contamination. THC can find its way into hemp-derived CBD oil through cross-contamination during the growing, harvesting, extracting, or manufacturing processes. This is more likely to happen at facilities that produce CBD oil derived from both hemp and marijuana plants.
  • Type of CBD oil. There are three different types of CBD oil — full spectrum, broad spectrum, and CBD isolate. These different varieties refer to what additional cannabinoids are retained during the extraction process.

Full spectrum CBD retains the full profile of cannabinoids and terpenes found in cannabis, and therefore contains trace amounts of THC. Depending on how much you use, enough THC may accumulate in your system to show up on a drug test. Broad spectrum CBD oil removes any trace amounts of THC, while retaining other cannabinoids and terpenes. CBD isolate is pure, isolated CBD that does not contain any other cannabinoids or terpenes.

III. How much THC must be in your system to show up on a drug test?

So if your CBD oil contains trace amounts of THC, does that mean you will automatically fail a drug test? Not necessarily. There is still a threshold that needs to be met in order for the test to show positive results.

Federal workplace drug testing cutoff values have been established for THC and the other chemicals that indicate the presence of drugs in someone’s system, so that trace amounts do not trigger a false positive.

The thresholds for detection vary based on the type of test:

  • Urine: The minimum threshold for THC or its metabolite, THC-COOH, in a urine test is 50 nanograms per milliliter. Depending on a number of factors, THC can remain in a person’s system and be detected anywhere from a few days to a few weeks. Generally speaking, individuals who use marijuana, which has a higher percentage of THC, can expect the chemical to remain detectable in their system anywhere from three to 30 days.
  • Hair follicle: This is a newer drug testing method that has been gaining popularity, as it can detect the presence of drugs in someone’s system as far back as 90 days. The common cutoff for THC in a hair follicle test is 1 picogram per milligram for an initial screening, and 0.05 picogram per milligram for a confirmatory screening.
  • Blood: These screenings are less common. Most drugs, including THC, are eliminated from the bloodstream rather quickly. There are currently no standardized thresholds for THC in blood tests, but in Colorado and Washington, the threshold for driving under the influence is 5 nanograms per milliliter.
  • Saliva: Oral fluid tests are also less common than urine or hair tests, and there is not an established threshold for THC. The current suggested cutoff is 4 nanograms per milliliter for an initial screening, and 2 nanograms per milliliter for a confirmatory screening.

IV. Can I safely use CBD without failing a drug test?

The only way to be completely sure you won’t fail a drug test is to refrain from using any substances that might trigger a positive result.

However, if you want to try CBD, there are a few steps you can take to ensure your CBD oil is as pure as possible.

It’s important to only buy CBD oils and products from reputable companies. As a new industry with little oversight, the onus is on the brands themselves to be responsible and honest about what goes into their products.

Before purchasing CBD products, research the company’s history, process, location, and reviews. A strong indicator of a company’s trustworthiness and quality is that they have their products tested by an independent third-party lab, and make the results available to customers. Knowing where the hemp is grown can also be an indicator of quality, as the industry is more established and regulated in certain states like Colorado and Oregon.

Always read labels carefully, and contact the company if you have questions about ingredients. Be sure that you are purchasing CBD oil made from hemp, and not marijuana.

Selecting a broad spectrum CBD oil or CBD isolate is safer than a full spectrum CBD oil, which is more likely to contain trace amounts of THC.

While it’s not 100 percent possible to say that using CBD won’t trigger a positive drug test result, these steps can help you use CBD safely and with peace of mind.

V. Additional Resources