Bridget Brennan reported this story on Thursday, April 9, 2015 12:35:00

BRENDAN TREMBATH: Hundreds of young Australians have reported having seizures, paranoia and heart problems after using synthetic cannabis.



In a survey of 18 to 25 year olds, 65 per cent admitted to trying synthetic cannabis, despite knowing the risks.



Many of the users bought the drug online, mistakenly believing it was legal.



Bridget Brennan reports.



BRIDGET BRENNAN: About 1,700 young Australians aged between 18 and 25 were asked about their experiences using synthetic cannabis.



After using it, some said they felt like they were going to die.



This 23-year-old man, who asked to remain anonymous, smoked the drugs for several months.



UNIDENTIFIED MAN: I smoked a lot of cannabis and the synthetic stuff was, like the normal stuff was starting to become weaker and the synthetic stuff was quite an intense high.



It was really easy to have too much and you'd just be like, you're vomiting, it'd be hard to move, you'd be very nauseous for a while and having it daily as well, you start getting real bad sweats during the day when you're not having it.



BRIDGET BRENNAN: He's no longer using synthetic cannabis.



UNIDENTIFIED MAN: I just decided enough was enough and I stopped, made new friends, moved to a new town.



BRIDGET BRENNAN: The survey found that the effects of the drugs were so strong that 75 per cent said they'd never use synthetic cannabis again.



Professor Jan Copeland headed the study; she's the director of the National Cannabis Prevention and Information Centre.



JAN COPELAND: One in 10 actually had a feeling that they were either dying, that sort of feeling of impending doom, or indeed that they had already died, which you can only imagine how frightening that would be, particularly for a young person.



BRIDGET BRENNAN: A quarter of the people who'd used synthetic cannabis didn't realise the drugs were illegal.



Professor Copeland again.



JAN COPELAND: It's so important to get out the message that these are not cannabis-related drugs.



They're synthetic chemicals, they aren't legal, they aren't safe.



They're also not a regulated market and it's not, you can't believe what they're telling you you're being sold.



BRIDGET BRENNAN: Richard Kevin is doing a PhD on synthetic cannabinoids at the University of Sydney.



He's found the chemical drugs can be 50 times as potent as regular cannabis



RICHARD KEVIN: These drugs are basically designed to mimic the effects of regular cannabis but they tend to be a lot stronger.



BRIDGET BRENNAN: Richard Kevin has been testing dozens of types of synthetic cannabis on rats and in rats, there's evidence the drugs can cause long-term memory loss.



RICHARD KEVIN: So far we've found strong anxiety producing effects and long term memory impairment, as well as decreases in heart rate and body temperature.



BRIDGET BRENNAN: In January, two men died in Mackay in Queensland after using synthetic cannabis.



Synthetic cannabis is sold under various brand names, with dozens of different chemical compositions.



The laws banning the drugs are complex, but most states started banning the chemicals in 2011.



But despite tighter restrictions, the drugs are still being sold in sex shops, herbal shops and online.



Professor Michael Farrell is the director of the National Drug and Alcohol Research Centre at the University of New South Wales.



MICHAEL FARRELL: What they're trying to do is bring in what's called analogue legislation, which means while one thing may be banned and another thing not be banned, that if it's similar in structure to that, that is banned well then, it can be seized or prevented from sale.



BRIDGET BRENNAN: Professor Farrell believes there are difficulties with policing the sale of synthetic cannabis.



MICHAEL FARRELL: One of the things that in a way has happened around a lot of this, has been, there's been a cat and mouse game around what some people, how they're developing drugs that fall out of the legislation et cetera et cetera.



But most of the time they haven't been doing that. They've simply been rebranding things, calling them something and selling them under false pretence.



BRIDGET BRENNAN: Researcher Richard Kevin says it's education, not legislation that will stop people using the drugs.



RICHARD KEVIN: I think our legislation is pretty good actually. These compounds aren't legal.



I think more of the problem is educating people about the risks of these compounds because we know that people use drugs even if they are illegal.



I think the key is making sure the message is out there that these drugs are not at all safe, there's no quality control and you can't know what you're getting.



BRENDAN TREMBATH: University of Sydney researcher Richard Kevin ending Bridget Brennan's report.