But having medical value” isn’t the same thing as “being a medicine.” A medicine is a material of known chemical composition and dosage that has been shown in clinical trials to be safe and effective in the management of some condition in some patient population. By that standard, natural cannabis can’t be a medicine, simply because natural cannabis varies so widely in its chemical content: not only from one strain to another, but from one plant to another and even from one bud to another from the same plant.
 
“Blow some weed” is not a prescription. That’s the reason that “rescheduling” cannabis to recognize its medical value is a non-starter legally; rescheduling needs to follow clinical research, and would apply only to specific products, not to the plant generically.