"Supplement" is a cop-out word. It means pretty much nothing

Cue the "supplements don't work" "articles" or even this one.

Yes, if you go to a fitness store, I'd say around 80% of that is at best harmless (some may have questionable substances - especially those "pre-workout" ones, and the "Prohormone" ones, which are usually worse than taking the actual steroids)