Use of so-called “full-spectrum” formulations of cannabidiol (CBD) products can cause users to test positive for THC, the component of marijuana that causes euphoria, according to an open-label study published in JAMA Psychiatry.
Full-spectrum CBD products contain THC, but at levels too low (≤0.30% by weight) to meet federal guidelines for Schedule 1 classification. To determine whether use of such a product might cause a positive urine drug test for THC, the authors enrolled 15 individuals being treated for anxiety to receive a full-spectrum, high-CBD extract containing 9.97 mg/mL of CBD (1.04%) and 0.23 mg/mL of Δ9-THC (0.02%), 1 mL sublingually 3 times per day for 4 weeks. Presence of THC was assessed using a presumptive test panel, followed by gas chromatograph-mass spectrometry performed by Quest Diagnostics.
Seven patients tested positive for THC, and 7 tested negative (1 patient dropped out).
“Despite limitations in sample size and diversity, these findings have important public health implications,” the authors concluded. “It is often assumed individuals using hemp-derived products will test negative for THC. Current results indicate this may not be true,” and the results may have “potential for adverse consequences, including loss of employment and legal or treatment ramifications, despite the legality of hemp-derived products.”
Dahlgren MK, Sagar KA, Lambros AM, et al. Urinary tetrahydrocannabinol after 4 weeks of a full-spectrum, high-cannabidiol treatment in an open-label clinical trial. JAMA Psychiatry. ePub ahead of print. November 4, 2020. doi: 10.1001/jamapsychiatry.2020.3567