Neurotoxic potential of synthetic cannabinoids' pyrolysis products

Synthetic cannabinoids (SCs) represent a prominent class of new psychoactive substances (NPS), primarily consumed via inhalation methods such as smoking or vaping. Although the direct neurotoxic effects of SCs are well established, the pyrolysis process that occurs during smoking induces structural alterations that generate novel, frequently unidentified toxicants with potentially severe neurobiological consequences. This review addresses the neurotoxicity associated with parent SC compounds and their pyrolysis products, with particular emphasis on mechanisms, including oxidative stress, mitochondrial dysfunction, excitotoxicity, and neuroinflammation. A PRISMA-guided systematic review identified only nine studies specifically investigating the neurotoxic effects of SC pyrolysis products, revealing a significant gap in the literature and underscoring the urgent need for targeted research in this domain. The review further highlights that additional constituents, such as plant materials incorporated into SC formulations, can contribute to the generation of harmful byproducts and complicate forensic interpretation. The structural heterogeneity of SCs, in conjunction with variables such as polydrug use and chronic exposure, further exacerbates their toxicological profile. Future research should prioritise the identification and characterisation of pyrolysis-derived toxicants, the advancement of analytical methodologies for their detection, and the implementation of evidence-based public health strategies aimed at risk mitigation.