Irish and British authorities should work together to fight the sale of illegal headshop drugs online, experts have said.
The number of high street stores selling the psychoactive highs fell from 102 early last year to 11 after a wide-ranging ban but there is a vast internet business supplying users, a review has found.
The National Advisory Committee on Drugs (NACD) said online sales are much bigger out of the UK but warned that it has uncovered a young and vibrant community of users in Ireland experimenting and discussing the effects on internet forums and chat rooms.
The anti-drugs body called for awareness groups to target users directly and dynamically through social media to highlight the dangers and side-effects of banned headshop drugs and new chemical highs.
Dr Des Corrigan, chairman of the NACD, urged the Irish Medicines Board and Customs to get together to crack down on shipments of drugs from overseas.
"While the number of headshops decreased significantly as a result of Government action, a challenge still exists in terms of the monitoring of online outlets for the sale and supply of new psychoactive substances," he said.
"There are a vast number of online retailers, many of which deliver to Ireland. The report found that while these online products may claim to be 'legal', the products which were analysed all contained illegal substances.
"In order to address this issue efforts could be made to examine existing models to curtail such trading, for example, through the co-operation between the Irish Medicines Board and the Customs authorities to monitor the sale of counterfeit medicines."
The NACD said many recreational users of cocaine, cannabis and ecstasy opted to use headshop drugs in 2010 before a ban out of curiosity and thanks to the availability. It said Ireland and Britain's close proximity and cultural ties should allow the two countries to collaborate to crack down on online supply.
Roisin Shortall, junior minister in the Department of Health, said state agencies would be brought together to try to tackle access to the drugs.