Clinical Trial: Hemp-Derived Products Containing THC Levels Below Federal Standards Trigger Positive Drug Test Results

Boston, MA: The daily ingestion of hemp-derived CBD products containing trace levels of THC can trigger a positive drug test result for marijuana, according to clinical trial data published in the journal JAMA Psychiatry.

A team of researchers affiliated with Harvard Medical School assessed the toxicological screens of 14 subjects who consumed hemp-derived CBD products daily over a four-week period. The CBD products were lab-tested and contained THC levels below federal standards (no more than 0.3 percent THC on a dry weight basis.)

At the end of the trial period, 50 percent of the subjects tested positive for the presence of the carboxy-THC metabolite on a urinary drug screen.

Authors concluded: “[T]hese findings have important public health implications. It is often assumed individuals using hemp-derived products will test negative for THC. Current results indicate this may not be true, especially if assays are more sensitive than advertised, underscoring the potential for adverse consequences, including loss of employment and legal or treatment ramifications, despite the legality of hemp-derived products.”

The ingestion of CBD products absent any presence of THC will not trigger a positive drug test result because CBD is not converted into carboxy-THC following metabolization.

Currently, the US Navy bans servicemembers from using CBD products out of concern that doing so may expose them to trace levels of THC.

Full text of the study, “Urinary tetrahydrocannabinol after 4 weeks of a full-spectrum, high-cannabidiol treatment in an open-label clinical trial,” appears in JAMA Psychiatry.