For previous Star Tribune stories about the rise in synthetic drug use, go to startribune.com/ lethaldose
• Retailers unsuccessfully tried to block a law on substances that mimic pot and LSD.
• Designer drugs can be purchased easily online, leading users to believe they are safer than street drugs. But the chemicals can be unpredictable --and disastrous.
• Synthetic drugs are widely sold as bath salts and incense. But lab tests reveal substances that can kill.
