Grandaddy Purple, Blueberry Yum Yum and other pot products may now be legal for medical use in 20 states and the District of Columbia, but how do patients know what dose they’re really getting and whether it’s safe? Small labs are setting up shop — some at their own legal peril — to help patients find out, according to an article in Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society.
