The law is failing to hold back the growing tide of dangerous 'legal' highs, drug experts have warned.
Untested substances mimicking banned drugs are for sale in Britain's takeaways, newsagents and pet shops - and they may be more dangerous than the drugs themselves.
"The chemistry is outstripping the law", Harry Shapiro, of DrugScope, told HuffPost UK.
TOP STORIES TODAY
He said new "designer drugs" were springing up all the time, often containing banned substances when they are analysed.
Young people are ending up in hospitals with convulsions and seizures after taking things with lurid names like Clockwork Orange and Exodus Damnation, DrugScope said.
But the law is ill-suited to tackle the problem and young people are not warned of dangers because the substances are marketing "not for human consumption".
"There doesn't seem to be much public awareness of how dangerous some of these substances are", said Shapiro.
Asked whether the so-called designer drugs could in fact be more dangerous than a substance like cannabis, he added: "Potentially they are, yes, but then again people do come unstuck smoking cannabis as well."
In a blog for HuffPost UK, writer Katie Winrow describes how she became addicted to legal highs after trying them to combat anxiety, for fear of being a criminal if she smoked marijuana.
"Within six months I had lost my house, my job and my sanity," she wrote.
Meanwhile, another expert suggested some some drugs should be given their own 'Class D' status and made legal.
Baroness Meacher said 'low risk' substances, including some types of cannabis and emerging legal highs, could then be safely regulated and labelled.
Meacher, who leads the European Initiative on drug policy reform and chairs the House of Lords all-party parliamentary group on drugs, told The Times: "Regulation would involve labelling, showing the risks and side effects of the drug, age limit and recommended maximum dose.”