New drugs that evade legal bans are being developed at such a rate that they now outnumber illegal substances, the UN Office on Drugs and Crime (UNODC) said Wednesday in Vienna.

Such "legal highs" mimic the effects of existing drugs like amphetamine, cannabis or khat but can be far more dangerous, as little is known about their side effects and their potential to cause addiction, the UNODC said in its annual report.

Countries had reported 251 new substances to the...read more here: New drugs that evade legal bans exploding