FROM OUR ARCHIVE: This article was originally published on May 28, 2014 and was re-published on May 21, 2015 after five students were hospitalised after reportedly taking synthetic cannabis
The influx of legal, synthetic forms of cannabis that can be more potent and dangerous than the natural, illegal drug exposes Britain's "utterly ridiculous" cannabis laws, it has been claimed.
Damaging new synthetic forms of the drug accounted for nearly a quarter of all new legal highs identified in Europe in 2013.
Last year, 29 new forms of "synthetic cannabinoids" were identified, out of 81 total new substances.
In 2012, 30 new forms of it were identified out of a total of 73 new legal highs.
The synthetic drugs can be more potent than their natural counterpart, as well as being mixed with chemicals that cause side effects.
In one case earlier this month, two teenagers were admitted to hospital after taking synthetic cannabis.
Steve Rolles, senior policy analyst at the charity Transform that campaigns for drug law reform, told The Huffington Post UK that having a more dangerous, legal version of the drug meant Britain's drug policy was "the worst of all worlds".
He told The Huffington Post UK: "Synthetic cannabis might be the straw that breaks the camel's back in terms of cannabis reform.
"We currently have an unbelievably stupid situation where people can buy fake cannabis that's more dangerous. It's utterly ridiculous.
"It's absolutely the worst of all worlds."
Synthetic cannabinoids are usually powders, many of which are manufactured in China and shipped to Britain in bulk. Once in Europe, the chemicals are typically mixed with or sprayed onto herbs.
They mimic the effect of tetrahydrocannabinol or THC, which gets people high.
Frank, the drug advice service, has said its most common risks are "an increase in heart rate, feeling on edge or restless, feeling tried or drowsy, feeling sick, being sick and hallucinations".
One synthetic cannibinoid, AM2201, can cause "panic attacks and convulsions".
Frank has also warned synthetic cannibinoids could have unknown side effects because the substances it contains are new.
Rolles told The Huffington Post UK that they can be more dangerous because they cannot be labelled to tell people how to take them safely or advise on dosage, as the law forbids their sale "for human consumption".
Because they are often more potent, people using them can overestimate the dose they should take to get high, Rolles said, adding this often meant people can ended up having a "terrible time" and have to go to hospital having taken too much.
He said: "A lot of the people don't know what they're taking or they don't know it can be more potent or dangerous."
Earlier this month, two teens were hospitalised in New Zealand after taking synthetic cannabis drug Illusion.
The pair, aged 13 and 14, were "in a moderate position" and suffering from dizziness, TV station One News reported.
New Zealand has just banned the sale of synthetic cannabis. The country's Department of Health said it expected up to 200 people to suffer withdrawal symptoms and require treatment.
Before the ban came into affect on May 1, many synthetic cannabis users stocked up on the stuff.
"I think I'll just stock up to be honest," one woman who uses them told 3 News. "I don't want to go back to marijuana."
Transform has said these drugs "form a key part" of the legal high market in the UK.
In its recent report, How To Regulate Cannabis, Transform said: "The synthetic cannabinoid market is fueled by cannabis prohibition, and will largely disappear when it ends, as most users report a preference for 'real‘ cannabis over synthetic alternatives."
The charity said "relatively little" is known about synthetic cannabinoids and the products that contain them.
Rolles said it was difficult to know for certain how prevalent the use of them in the UK it was, because of the variety of products used to contain them and the fact they are not expressly sold for people to take.
He said the best available data was the annual Global Drugs Survey - the most recent showed British people take the most legal highs of any of the countries that took part, with 12% of people admitting to taking them in the last year.
Rolles told HuffPost UK most cannabis users preferred the natural drug to the synthetic alternative.
He added the relaxed drug laws of the Netherlands meant there was no market for synthetic cannabis there, which demonstrated people would buy the plant if they could.
He said: "The place where there's no market for this stuff is the Netherlands. It's prohibition that creates the demand for these products - not the people who buy this stuff."