HHC, which has been linked to episodes of psychosis and hospitalisation, has been categorised as a Schedule 1 controlled drug under the Misuse of Drugs Act 1977, criminalising its import, export, production, possession, sale, and supply.

Schedule 1 controlled drugs are those which have little or no therapeutic value and which present a very high risk of abuse.

Other drugs, including synthetic opioids, have also been newly classified as controlled drugs following their identification by the the EU and by the UN Commission for Narcotic Drugs as posing a serious risk to public health.

Jennifer Carroll MacNeill, the health minister, 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.

“Under the successor national drugs strategy, I’m committed to reviewing legal avenues to respond faster and more effectively to emerging threats from by the volatile drugs market.

“In line with our health-led approach to drug use, our priority is to advance measures that enable us to protect and support the health of our population.”

Jennifer Murnane O’Connor, the minister for public health, wellbeing and the national drugs strategy, added: “HHC, like other synthetic and semi-synthetic drugs, is a grave threat to public health.

“Controlling HHC and other harmful substances is an important step that must be complemented by education and prevention programmes so that young people and parents are better informed about the risks associated with drug use.”

Mary Butler, the minister for mental health, added: “A recent study showed HHC was involved in a third of first-time psychosis cases at University Hospital Galway. This is clear evidence of the serious harm it can cause.

“Classifying HHC as a Schedule 1 controlled drug will curtail its availability and reduce its health impact, particularly on the mental health of younger people.

“Measures like this are essential to easing the pressure on our mental health services and protecting individuals, especially those unaware of the risks, from avoidable and significant harm.”