Substances of Health Concern: Label Accuracy of Cannabidiol and Tetrahydrocannabinol in Commercial Cannabidiol Tinctures from the United States.

Introduction: In recent years, the production and consumption of cannabinoids have increased significantly. Researchers are particularly interested in cannabidiol (CBD), Δ⁸-tetrahydrocannabinol (Δ⁸-THC), and Δ⁹-tetrahydrocannabinol (Δ⁹-THC). Despite the growing prevalence of these molecules in everyday life, research shows that cannabinoid products are often mislabeled. In this study, we quantified and compared the label accuracy of CBD in full- and broad-spectrum tinctures to evaluate whether there is a public health concern related to CBD, Δ⁸-THC, and Δ⁹-THC. Materials and Methods: A total of 18 samples from different brands sold online in the United States were obtained for the study. Reverse-phase high-performance liquid chromatography with ultraviolet/visible light detection (RP-HPLC-UV) was employed to detect and quantify the concentration of CBD and THC isomers within the samples. Labels were deemed inaccurate if the actual concentration of CBD deviated by more than 10% from the labeled amount. Results: Our findings showed that 12 out of 18 samples had inaccurately labeled CBD concentrations. Notably, a significant difference in CBD label accuracy was observed between broad- and full-spectrum tinctures (p = 0.0282). No significant correlation was found between the cost of the tinctures and the label accuracy for CBD (p = 0.2117). While none of the broad-spectrum tinctures contained Δ⁸-THC, two contained Δ⁹-THC. All full-spectrum tinctures contained both Δ⁸-THC and Δ⁹-THC at levels below the federal limit for hemp of 0.3% on a dry weight basis. Discussion: Accurate labeling of CBD and THC in tincture products is a crucial public health concern, both locally in Texas and across the United States. There is a need for the U.S. Food and Drug Administration to promulgate regulations for labeling products that contain CBD and THC.