From the article:

> Many people are, however, concerned about pharmaceutical content in the urine. "It's the biggest question we get," Shupack says. REI has conducted research to find out just how much of common drugs like caffeine and the painkiller acetaminophen are evident in vegetables grown using urine fertiliser. The final results are yet to be released, but the preliminary findings suggest the amount of pharmaceuticals in vegetables fertilised with urine to be "extremely small". "You'd have to eat a pretty obscene amount of lettuce, every day, for way longer than you can live" to get a cup of coffee's worth of caffeine, Shupack says.