Challenges in Regulating Synthetic New Psychoactive Substances: Lessons from Japan's Generic Scheduling against Hexahydrocannabihexol

On December 2, 2023, Japan's Ministry of Health, Labour and Welfare (MHLW) announced an ordinance regulating the possession, consumption, and distribution of hexahydrocannabihexol (HHCH) except for medical purposes. HHCH, a synthetic cannabinoid, has been linked to central nervous system symptoms, including nausea, dizziness, and numbness, presumably due to its structural similarity to tetrahydrocannabinol. This regulatory action reflects Japan's historical drug regulation approach, which has evolved to address synthetic substances not covered by earlier laws. The emergence of new psychoactive substances has led to increased poisoning cases and necessitated Japan to introduce a generic scheduling system and collectively regulate these compounds. Despite the reduction in designer drug-related arrests following system implementation, recent trends have shown a resurgence in arrests, partly because of the increased online accessibility of these substances. The persistence of HHCH gummy manufacturers highlights the limitations of current regulations. Thus, enhancing health literacy and social responsibility among consumers and proactive measures by healthcare professionals are essential to mitigate the public health risks associated with these emerging substances. Regulatory frameworks should prioritize public health over economic benefits.