Health Effects of Delta-8, Delta-9, and Delta-10-Tethydrocannabinol and New Unregulated THC 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 a great concern for their health effects. Previous novel lung injury outbreaks, namely 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. Federal regulatory policies like the United States 2018 Farm Bill classify hemp 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 regulatory loophole 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 on the market. 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 potential therapeutical uses, toxicity, pharmacology, and possible health risks of several THC and hemp-derived cannabinoids. This review also draws insightful highlights to the public health consequences of secondary exposures to CBD and THC, and their molecular mechanisms of actions. It underscores the urgency for a strict regulatory oversight over unregulated cannabinoid markets to prevent other vaping-related health crises and other rapidly emerging cannabis health disorders, like the cannabinoid hyperemesis syndrome (CHS).