Toxicity and health effects of delta-8, delta-9, and delta-10-tetrahydrocannabinol and unregulated cannabinoids in vaping products

Hemp-derived cannabinoids (CBDs) such as Δ8- and Δ10-tetrahydrocannabinol (THC) in cannabis e-cigarettes have been growing in popularity among youth, causing great concern for their health effects. Previous novel lung injury outbreaks, such as E-cigarette or Vaping Use-Associated Lung Injury (EVALI), were associated with the rising use of e-cigarettes and vaping products. Toxicological studies have revealed that chronic exposure to cannabis vapor can cause adverse brain and pulmonary effects. Hemp products are classified as cannabis and set a limit of no more than 0.3 % Δ9-THC, while products containing more than 0.3 % are defined as 'marijuana.' This has led to the proliferation of hemp-derived intoxicating cannabinoids, such as Δ8- and Δ10-THC, in addition to cannabidiol (CBD), cannabinol (CBN), cannabigerol (CBG), and Δ9-THC appearing in combination products. CBD frequently serves as a significant component of hemp-derived formulations, making it a central consideration for toxicological and regulatory evaluation as well. This phenomenon poses significant health risks to youth because these newer THC isomers and products are currently unregulated and not well-researched, yet they are still widely available. Therefore, we have examined the pharmacology, toxicity, potential therapeutic uses and possible health risks of several THC and hemp-derived cannabinoids. This review draws insightful highlights to the public health consequences of secondary exposures to CBD and THC, and their molecular mechanisms of action. It underscores the urgency for a regulatory oversight over unregulated cannabinoid markets to prevent toxicity of vaping-related health crises and other rapidly emerging cannabis health disorders, like the cannabinoid hyperemesis syndrome (CHS).