Medicinal plant liquid (Better than redbull) !?

Hey guys! I used to work in a restaurant 5 or 6 years ago and some guy bought a white bottle ( I think it was a 1L, but i'm not sure what the size of the bottle is) And it was filled with black liquid, I swear it tasted like crap, and by the way it looked you could even compare it to tar. Anyway he told me to take a sip, I swear, I only took half of the cap (around 5 ml of liquid) and my arms just start moving by itself, it was ridiculous how it worked. I've been trying to find some more info on that bottle, but I really don't know where to look. I think he bought it at some illegal place, but i'm really not sure, it's way too far back. I'm sure it's ginseng, but I don't know why I can't find anything like this on the internet, is it still available? Anyway thanks !