One of the more common questions we get from our clients revolves around the use of CBD oils and how they affect drug screens.

What is CBD?

CBD is short for Cannabidiol. THC and CBD are two of the chemicals found in both cannabis and hemp plants. Depending on the species of the plant, it will either be high in THC and low in CBD, or low in THC and high in CBD. THC is the psychoactive chemical that causes intoxication and shows up on drug test results. CBD is non-intoxicating and does not show up on drug screens.

Over the past few years, CBD has gained notoriety in the news and has been suggested to be helpful to treat epileptic seizures, anxiety, inflammation, sleeplessness, and a host of other maladies. Depending on who you listen to, CBD is either a miracle cure or the latest snake oil.
The truth is that limited scientific studies have been performed because of the negative stigma that until recently has been associated with marijuana. Even now, the FMCSA is only allowed to study relatively mild versions of marijuana with Federal grants.

How does this affect drug screens?

CBD will not cause a lab-based drug screen to show as positive. The issue is that it is impossible to be certain what is in a bottle labeled “CBD Oil”. These herbal supplements are not regulated by the FDA. A bottle could contain CBD, olive oil, or very high THC. If an employee tests positive for THC, a competent MRO will not accept statements of CBD oil or second-hand smoke as acceptable reasons to overturn the test (See 49CFR§ 40.151(d)).

What if marijuana is legal in my state?

Legal marijuana use is gaining ground across the nation. While no one wants a “high” employee, many people today believe that recreational marijuana while off the job is no more dangerous than a few beers.

The difference between testing for alcohol and THC is that there is no drug test at this time to detect “impairment” due to THC. Federal law still considers THC to be a Schedule I (illegal) drug. If your drug test is a Federal test, state licenses or prescriptions should not be acceptable reasons for the MRO to overturn the drug test.

If your test is non-Federal, the answer gets a bit more complicated. Say your employee, from Colorado, where recreational use is legal, takes a test in New Mexico, where medical use is legal, for a job in Texas, where there is no legal use. The MRO can’t possibly make a safe determination in these conditions. CMS policy for THC positives is to inform the employer and let them determine if the job duties of the employee allow them to use marijuana.

Is CBD legal?

This is an interesting question. You can legally buy CBD oil at hundreds of retail markets and over the internet, but as recently as May 4, 2018, a Federal appeals court has upheld the DEA decision that CBD and other marijuana extracts are Schedule I (illegal) drugs.

Are there any acceptable, legal, uses of marijuana?

Actually, yes! There are FDA approved drugs Dronabinol and Nabilone that contain synthetic THC. Given during medical procedures, they have been shown to reduce anxiety and fight nausea. The patient is always advised that it may cause a positive drug test, and proof of the prescription is acceptable for the MRO to overturn the drug test to a negative before reporting to an employer.

I think my employee is high, but they have a prescription for Dronabinol. What can I do?

One way of getting around the system is for a doctor to write a prescription for Dronabinol, and then tell the patient to smoke all the marijuana they like. If they have to take a drug test, the Dronabinol prescription will validate the THC in their system. There is a supplemental test that CMS can perform at the request of the company called a THC-V test. The THC-V (See 49CFR§40.141(b)) test can determine if the positive THC was due solely to a Dronabinol prescription, or if marijuana was used.

Bottom line

CBD will not show up in drug tests, however since herbal supplements are not regulated by the FDA, many CBD oils may contain THC or other undesirable chemicals. CBD use is not an acceptable reason for an MRO to overturn a positive test.

CMS has been a reliable MRO for over 22 years. We have helped thousands of clients navigate DOT regulations and workplace issues with qualified drug test review and expert advice. We are happy to help. If you have further questions, please email [email protected] or visit us at