The number of drugs in the world is enormous and continuously in change; any person know the exact number. For the classes of pharmaceutical drugs see the link bellow.
I used hair dye on drugs in the world.
Pretty much everyone in the world use drugs.
In 1951 the Durham-Humphrey Amendment established two classes of drugs; Legend and Over the Counter drugs.
Drugs are put into different classes because of the different things that they do to you and your mind. ex: Hallucinogenics give you hallucination.
Class b
Classes
3
Thousands upon thousands. There are illegal and legal drugs if that's what you mean, but there are so many drugs.
up to 100
hallucinogen's, depressants and stimulants
As many as you believe. The world is your oyster! Don't do drugs.