Illegal substances

In my everyday I meet a lot of folks who suffer from substance use issues and what bothers me is how little I know about where these modern substances actually come from and who is making/trading them. The reason I wish to understand this is the way I think drug trade is tied to capitalist exploitation and hightens it on all levels. The way these substances make people vulnerable to be exploited is the end of this that I see every day, but I never see the other end.

I am talking about stuff like alpha-pvp that does incredible harm to people and seems very potent. Every search I do leads me to Western articles that blame China or name China as the origin of these. But is it really?

If there us any good non-propagandized sources you could share, I would really appreciate that.