Cannabis
In the 2010s many countries and some states in the United States made it legal for people with certain medical problems to use cannabis as a medicine.  Medical use of cannabis is legal in Austria, Belgium, Canada, Chile, Colombia, the Czech Republic, Finland, Greece, Israel, the Netherlands, Spain and the United Kingdom.  In March 2017 Germany legalised cannabis for medical use with treatment of pain and symptoms by chronic diseases.  Only a few companies and doctors in Germany willingly prescribe cannabis for medical uses.  Not much known about the broad spectrum of medical cannabis efficacy as the drug is still listed under the German narcotics act (in German "Betäubungsmittelgesetz" or abbr. "BtMG").