Are CBD products detectable in a drug test for THC or marijuana?

Testing for illegal drug use is a reality for many workers. Although it is not required in the private sector, more and more employers are conducting some type of drug screening. When drug testing is mandatory, employers almost always follow the regulatory guidelines because they provide them with a solid legal basis. The testing guidelines usually overlap with the accepted limits for drugs and drug metabolites in confirmatory testing and screening.

Since it is well known that THC is responsible for the psychoactive and euphoric effects of marijuana, routine urine tests for marijuana use consist of immunoassays with antibodies to detect THC and its major metabolite, 11-nor-delta9-carboxy-THC (THC-COOH). For example, US SAMHSA (Substance Abuse and Mental Health Services Administration) has set the threshold for a positive urine immunoassay test at 50 ng/ml. If the screening immunoassay test is positive at a level greater than 50 ng/ml, a confirmatory GC/MS (gas chromatography/mass spectrometry) test is performed to verify the positive urine screen. The confirmatory GC/MS has a cut-off value of 15 ng/ml and is specific only for the metabolite 11-nor-THCCOOH.

Is CBD detectable in a drug test?

Fortunately, urine tests for THC-COOH are known to have very low reactivity to other non-intoxicating cannabinoids such as CBD (cannabidiol), CBG (cannabigerol), CBN (cannabinol) and others. This is good news for “normal” CBD/hemp oil users.

Nevertheless, individuals taking unusually high doses of a cannabinoid-rich hemp oil product (over 1000-2000 mg of hemp oil per day) could theoretically test positive on initial urine screening. Although very rare, urine screening in these cases would likely represent a “false positive” caused by metabolites or compounds other than THC that may cross-react with the immunoassay. In this case, the GC/MS confirmatory test would be negative because CBD and other cannabinoids cannot be detected by the more accurate (and specific) GC/MS screening.

Note that most high-quality and reliable CBD-rich hemp oil products contain much less THC than marijuana. For example, hemp contains 1/10 to 1/300 of the THC concentration of marijuana. Thus, a person consuming 1000-2000 mg of hemp oil per day would be ingesting about 3-6 mg of THC. This extremely high dose can lead to a positive urine test in up to 11-23% of tests.

On the other hand, there are data showing that at a daily dose of 0.5 mg THC from 3 to 5 servings of most commercial CBD-rich hemp oil products, the rate of positive urine tests is < 0.2 %. Again, most servings of typical high-purity CBD-rich hemp oil products contain much less than 0.1 mg of THC, more than 400-600 times less THC than marijuana products.

What does all this mean? Simply put, it is very unlikely that a consumer using a high-quality, scientifically validated hemp product in a standard serving size will test positive for THC and/or THC-COOH. However, it should be noted that extremely high doses may result in a positive urine test (which would later be shown to be false by GC/MS). Ultimately, consumers need to be fully informed of their employer’s specific regulations and adjust their use of cannabinoid products accordingly.

Note: Most research suggests that for infrequent or “non-daily” cannabis users, a typical high-dose marijuana cigarette (containing about 40 mg to 50 mg of THC) would test positive for THC metabolites for up to two days at this threshold. However, for usual and regular cannabis users, the same screening can be positive for several weeks, depending on many factors, including :

• how much and how often cannabis is consumed
• the metabolism of the person tested
• the method of administration
• other factors such as medication taken, liver or kidney disease, etc.

This article is based on US SAMHSA standards. Other organisations’ drug testing standards may vary. Therefore, please note that the results presented in this article may differ under alternative standards. If you are concerned about testing positive for THC when taking hemp oil containing CBD, please consult your health care provider.

If you are worried about a positive test result for THC or marijuana after taking CBD products, see How to get THC out of your body in 4 steps.