Scientific research into the medicinal uses of cannabis has ramped up in recent years, as more governments move to decriminalise the drug.
We now know that the CBD element of cannabis has a host of therapeutic applications. The irony is that our predecessors had been using medicinal marijuana for at least 3,000 years.
Body of Evidence is a video series from BBC Future unravelling medical myths and curious health conditions.
Video script: Harish Suthi, from the Department of Science and Technology Studies, University College London.