It follows the death of 17-year-old Adam Owens in Newtownards, County Down, on Monday.
His family blamed his death on an addiction to "legal high" drugs and has called for a ban on them.
Mothers Against Drugs said it is concerned about how effective the law is at tackling legal highs.
Donna McMenamy helped to found the group after her 12-year-old son became addicted to the drugs in 2012.
He is currently receiving treatment for his addiction, and is not using drugs at the moment, but she said more needs to be done to help ensure he does not start again.
"He has got fed up and went back onto drugs again in the past," she said.
"The system's very slow, there is no money, no resources and that really needs to change. When people put their hands up for help it needs to be there for them."
Mrs McMenamy said those responsible for selling legal highs were "animals".
"They don't care what it's doing, not just to the person themselves but the surrounding families and the effect it's having on the community too."
Randox Laboratories in County Antrim is a specialist hub for "legal highs" drugs analysis.
Toxicology manager Mark Piper said long-term use of legal highs could have serious consequences.
"There are lots of negative effects," Dr Piper said.
"Besides the short-term stimulation, it can lead to extreme violence, extreme apathy and can really affect people's personalities."
He added that the use of legal highs is continuing to increase across the UK.
"We are one of the biggest marketplaces for these substances within Europe, and we're continuing to see a rise of these being sent to Randox."
Fra Stone works with the Falls Community Council's drugs programme.
He said Northern Ireland's government needs to "pick up the pace" and enforce new legislation on legal highs.
"The wheels are grinding too slowly," he said.
"We need to toughen up. In the Republic of Ireland they had a ministerial order and were able to ban these overnight. In the jurisdiction we're in, it's a deferred matter that has to go to Westminster."
Several deaths in the UK have been linked to legal highs.
More than 200 of the substances have been banned since the coalition government came to power in 2010.
In the Republic of Ireland, "legal high" drugs are banned by law.
Emergency legislation was put forward in March after a loophole in the law meant that it was legal to possess drugs such as ecstasy, crystal meth and ketamine.
A Belfast based anti-drugs group has called for tougher laws to be introduced to deal with the sale of "legal high" drugs.