Semi-synthetic cannabinoids (SSCs) have emerged as a growing public health concern in Ireland despite recent legislative efforts aimed at restricting their sale. A recent article published in the Irish Journal of Psychological Medicine warns that these cannabis-like substances continue to be widely available across the country and may pose serious risks to both physical and mental health, particularly among young people.1 The authors argue that Ireland’s delayed response to the rise of SSCs highlights significant weaknesses in drug policy and enforcement systems that require urgent reform.

SSCs first gained international attention following the legalisation of hemp cultivation in the United States (US) in 2019. The change in legislation allowed manufacturers to extract cannabidiol (CBD) from hemp and chemically convert it into psychoactive compounds such as hexahydrocannabinol (HHC) and delta-8-tetrahydrocannabinol (Δ8-THC). These substances are often marketed in vape products, edibles, and oils as legal alternatives to cannabis. By 2025, SSCs had spread throughout Europe and were detected in 27 countries, including Ireland.

Although marketed as safer or ‘legal’ forms of cannabis, evidence increasingly suggests that SSCs can cause serious health problems. Reports from poison centres in the US recorded thousands of cases of Δ8-THC poisoning between 2021 and 2022, with many incidents involving children who accidentally consumed edible products mistaken for sweets or confectionery. Some cases required intensive medical treatment, demonstrating the potentially dangerous effects of these compounds.

In Ireland and across Europe, concerns have grown regarding the psychiatric effects of SSCs. HHC and related compounds have been linked to episodes of psychosis, anxiety, hallucinations, and dissociation. Research from University Hospital Galway found that more than one-third of first-episode psychosis patients admitted between 2023 and 2024 reported HHC use prior to their hospitalisation.2 Findings from Ireland’s European Web Survey on Drugs also revealed that many users experienced significant negative psychological effects after using HHC products.3

In response to these concerns, Ireland banned HHC and several related substances in July 2025 under the Misuse of Drugs Act, 1977. However, the article argues that this action came far too late. Many European countries had already introduced restrictions months earlier, while Irish retailers continued openly selling HHC products. Even after the ban, businesses quickly adapted by marketing new ‘HHC alternatives’ and cannabinoid blends that appear to fall outside current legislation. This rapid evolution mirrors previous trends seen during the rise of ‘head shops’ and new psychoactive substances in Ireland during the late 2000s.

The authors believe that Ireland’s response demonstrates a broader problem with reactive drug policy. Instead of addressing emerging substances before widespread harm occurs, authorities often wait until significant health consequences have already been reported or international controls are introduced. The article calls for a review of why existing legislation, including the Criminal Justice (Psychoactive Substances) Act 2010, was not used more effectively to regulate HHC earlier. 

Ultimately, the article emphasises the need for stronger early warning systems, faster legislative action, and closer collaboration between policy-makers, clinicians, researchers, and public health experts. As the market for SSCs continues to evolve, the authors stress that Ireland must develop a more proactive approach to drug regulation in order to protect public health and prevent future harm.

1    Bond B and Cannon M (2026) Semi-synthetic cannabinoids remain a potent concern in Ireland. Ir. J. Psychol. Med. Early online, pp. 1–2. Available from: https://www.drugsandalcohol.ie/45192/

2    O’Mahony B, Lanigan S, Lally N, et al (2025) Novel substance, same old problems: Admissions of psychosis precipitated by hexahydrocannabinol, a widely available semi synthetic cannabinoid. BJPsych Bulletin 1–6.

3    Mongan D, Killeen N, Millar SR, Matias J, Keenan E and Galvin B (2025). Hexahydrocannabinol (HHC) use and harms in Ireland: New findings from the 2024 European Web Survey on Drugs. Int. J. Drug Policy 145, 105011. Available from: https://www.drugsandalcohol.ie/44244/