This is not the point, however. Even if cannabis were a potent poison, adults have the absolute right to put anything into their bodies that they please. Doing so is not a crime. It has never been a crime. It will never be a crime.
Crimes have victims.
Smoking and selling cannabis has no victim. Only the initiation of force against another person or their property is a crime. Crime may not be legislated into being. They are all guilty of assault and kidnapping or conspiracy to commit assault and kidnapping. But even this isn't the point.