A mixture of of extracted hemp CBD and coconut oil is transferred to capsules at Colorado hemp company CBDRx. (Kira Horvath, Daily Camera file)

Drug testing and CBD: Can a cannabidiol user test positive for marijuana?

Ask The Cannabist: Experts weigh in about urine tests and whether the plant compound cannabidiol would result in a positive result for marijuana

Hey, Cannabist!
Will using CBD products create a positive drug test result for marijuana?
–Cannabinoid Claire

Hey, Cannabinoid Claire!
As you likely already know, cannabidiol (CBD) is a non-intoxicating compound found in both marijuana and hemp. It’s one of numerous natural plant cannabinoids, which include psychoactive tetrahydrocannabinol (THC).

CBD, reputed for its health benefits, is most widely known for treating rare seizure disorders in children. People try CBD products for other reasons too.

Dr. Ethan Russo, a neurologist and psychopharmacology researcher, notes in a 2011 study that the therapeutic effects of CBD are broad, including: analgesic, anti-inflammatory, antioxidant, anti-emetic (prevents vomiting), anti-anxiety, anti-psychotic, anti-convulsant and cytotoxic in certain cancer cells.

Russo really knows his stuff by the way — in addition to being a medical doctor and researcher, he served as president of the International Cannabinoid Research Society and chairman of the International Association for Cannabinoid Medicines.

Generally, CBD products are primarily made from the concentrated extract of the flowers, leaves and possibly stalks of marijuana or hemp. Most CBD products are either oil-based tinctures or capsules that are consumed orally, or topicals applied to the skin; however, there is a growing variety of other products containing CBD, including those for pets.

To find out if CBD would show on a urine drug test, I consulted employment drug testing expert Barry Sample, who is the director of science and technology for Quest Diagnostics, one of the larger diagnostic testing firms in the U.S.

“If the product contains only CBD and has had the THC removed, then an individual being tested would not be expected to test positive for marijuana or marijuana metabolite,” Sample says via email.

For good measure, I contacted marijuana health and science researcher, Paul Armentano. Armentano says via email: “Not unless those products also contain quantities of THC. Drug tests screen for either THC or the carboxy-THC metabolite, not for CBD.”

Both experts agree: As long as there is no THC in the CBD products, then a urine test would not yield a positive result for THC metabolites.

Sounds good, but there may be minute amounts of THC in your CBD products. An aspect in cannabinoid compounds that aids efficacy is the entourage effect. Coined by venerable Israeli cannabis researcher Raphael Mechoulam in 1999, the entourage effect is the belief that the compounds in cannabis work better together than if the compounds are isolated. CBD products, in addition to the CBD cannabinoid, may contain additional cannabis compounds, including THC, to  purportedly increase the effectiveness of the product.

From a regulatory standpoint, the U.S. Food and Drug Administration (FDA) has federal oversight over this nascent marketplace. In February 2015 and again in 2016, the FDA sent out warning letters to a handful of CBD companies. The letters focused on CBD content that didn’t match product labeling and improper medical claims made on websites. Lab analysis revealed some consumer products had a fraction of CBD claimed on the label. As of March 9, the FDA hadn’t yet issued any warnings for 2017.

As a consumer in this relatively new market, especially one who takes drug tests, research the products carefully. Look on the company or product website and assess the credibility and transparency of the company. Make sure you see analytical test results of the same product lot number you are consuming. It’s important to be confident in the company supplying your CBD products by knowing the potency and safety of the products.

Rumor control

One more topic related to CBD and positive drug tests: Some people may cite a study that says CBD converts to THC. While this is true in a limited scope in the lab, there is likely no reason to be alarmed in everyday life.

In the March 2017 edition of the Trends in Pharmacological Sciences journal, Russo takes a look at some “Cannabidiol Claims and Misconceptions.” Yes, there is a study that shows CBD converts to THC “after prolonged exposure to simulated gastric acid” in lab experiments. This study has been known in science circles since 1940 and is not new information. Russo writes: “There is no evidence that the reaction occurs in vivo in humans.”  Good to know that Russo is confident in stating CBD does not convert to THC in an actual stomach.

Just to reiterate: If you take CBD products and need to submit urine drug tests, request and examine lab reports to make sure your CBD products contain exactly what you are expecting. But know that in this largely unregulated market, it’s ultimately buyer beware.

Hope this information is helpful! XO


Ask The Cannabist: Clearly you have questions about marijuana, be it a legal concern, a health curiosity or something more far-reaching. Email your queries to askthecannabist@gmail.com.