Ireland’s delay in banning a semi-synthetic cannabis product may have contributed to its rapid spread across the country, according to new research showing that HHC use became “widespread” in a relatively short timeframe.
Hexahydrocannabinol (HHC) remained legally available through vape shops and high street stores until the Government banned its sale in July 2024, despite mounting medical concerns. The first European population study of HHC use suggests this regulatory lag may have boosted the substance’s popularity.
Research by the Health Research Board, HSE, and UCC’s School of Public Health examined data from 2,314 Irish participants in the 2024 European web survey of drugs. The findings revealed significant usage rates: 36% reported lifetime use, 33.5% had used it in the past year, and 18% had consumed HHC within the previous month.
The study, published in the International Journal of Drug Policy, found that high street stores were the primary source for 62% of users, with online retailers accounting for another 16%. Vaping was the most common consumption method at 85%, followed by edibles like candies and gummies at 34%.
Easy store availability drove initial use for 61.5% of respondents, while 46.1% cited safety perceptions from purchasing in legitimate retail outlets. The legal status may have created dangerous misconceptions about the substance’s safety compared to controlled cannabis products.
Users reported consuming HHC primarily to get high or for recreational purposes (62.9%) and to reduce stress or relax (51.9%). However, many also used it for self-medication: 27.3% for depression or anxiety, 18.2% for pain or inflammation, and 5.6% to manage cannabis withdrawal symptoms.
The research revealed concerning health impacts, with 90% of users experiencing negative effects and nearly a quarter reporting multiple adverse reactions. The most frequent problems included anxiety or panic reactions (15%), feeling faint or dizzy (13%), and dissociation or depersonalization (12%). Four percent reported hallucinations or psychosis.
The study noted that despite existing legislation like the Psychoactive Substances Act 2010, HHC remained legal “long after its psychoactive properties were confirmed” and was eventually controlled under the Misuse of Drugs Act rather than psychoactive substance laws.
Medical experts had raised concerns about HHC since late 2023, when four Cork teenagers were hospitalized after vaping the substance. By May 2024, HSE addiction specialist Eamon Keenan reported that approximately 20% of young people presenting to adolescent addiction services were associated with HHC use.
The researchers suggest Ireland may need to review its drug legislation to enable swifter responses to rapidly evolving drug markets. They noted that HHC products may contain harmful contaminants from production processes, adding to health risks beyond the substance’s unknown long-term effects.