National ban on HHC welcomed in Mayo after residents reported the products being sold to young people
The drug Hexahydrocannabinol (HHC) has been categorised as illegal under the Misuse of Drugs Act 1977.
The semi-synthetic cannabinoid has been designated as a Schedule 1 controlled drug, along with 13 other substances, by the Department of Health today.
HHC is reported to have similar effects to cannabis, with potential adverse reactions ranging from mild symptoms to severe poisoning that may require hospital treatment. According to the HSE, other risks associated with the drug are: depression, confusion, paranoia, delusions and withdrawal symptoms following frequent use.
Concerns about HHC products being sold in Mayo were raised to Castlebar councillor Harry Barrett, who reported the issue to local Gardaí.
“Unfortunately at the time I did report it, it was legally available in shops,” he told the Irish Independent, “They have to ban these psychoactive substances in vape shops, we don't know the origins or the quality control involved in them.”
The Royal College of Psychiatrists released a study carried out by researchers in the School of Medicine at the University of Galway earlier this month. They reviewed medical notes of individuals who had been admitted to University Hospital Galway with acute psychosis over a 21-month period.
The study revealed that HHC use was linked to one-third of first-time psychosis cases, and has now become the second most frequently identified drug in psychosis-related hospital admissions. Notably, the admission rate associated with HHC remained relatively steady throughout the study period.
Separately, research carried out by the National Drug Treatment Reporting System (NDTRS) between January 2024 and July 2025, recorded 221 treatment cases linked to HHC use. The majority of those treated were men aged 19 or younger.
A statement released by the Department of Health said: “HHC is one of 14 new substances, including several semi-synthetic cannabinoids and a novel benzodiazepine that have been newly classified as controlled drugs. This was done by a Declaration Order made by the Government of Ireland on 29 July 2025.”
Minister for Health Jennifer Carroll MacNeill said: "The sale of HHC as vapes, in attractive packaging, or in edible jelly form, is a marketing ploy aimed at young people, which masks the fact that this drug is harmful for youth mental health and can be addictive.”
When Cllr Barrett first learned that HHC products were being sold locally, residents raised concerns that young people were buying them before concerts.
“An overdose of these substances can destroy a young person’s mental health for life. This is what we are dealing with here,” he said, “Psychosis can be life long, we can't afford to have this in our town.”
He said it was great to see the government acting immediately on this issue but emphasized the need for strong legislation to prevent future variations of HHC entering the market.
“The problem I have is that any new legislation must cover other products that could stem from this, because there is nothing stopping another batch of a different type of substance coming out. I'm worried in case the legislation doesn't cover any other products that might morph out of this.”
This report has been funded by the Local Democracy Reporting Scheme.