The medicinal use of cannabis is beginning to be regulated worldwide. A plant that could well have been classified as medicinal, in the same way as opium poppy or so many others, has been perceived throughout the 20th century merely as a narcotic, but this is a very reductionist view of its nature. This article tries to explain the current state of what is also a big business in its infancy. Shot for El País Semanal in 2018. Article by Jesús Rodriguez.