Whats the difference between a class A and a class C drug?

Class A drugs are totally illegal %26amp; cannot even be prescribed by doctors (cannabis, LSD)


Class B %26amp; C drugs are controlled drugs that may have a medical benefit %26amp; have to be prescribed by a doctor. (class b: heroin, morphine, pethadine, cocaine %26amp; class c: diethylpropion and some slimming aids).