I do drugs quite a bit. Not weed so much, because I really just don't get much out of it. Maybe other people get different effects.. But whenever I smoke, I get paranoid, worried, insecure, etc. and it sucks, especially if I'm trying to get girls. Weed is definitely not a performance enhancer when it comes to this.
On the other hand, I think other drugs can be very helpful - not in a way related to women but as a method for personal growth (I'm talking about hallucinogens here). Tripping every now and then always kinda "refreshes" me when I'm feeling burnt out, and gives me new insights into the way my life is going, what I should change, etc. Probably not for everyone, but it's good to me.
Oh yeah, and drinking rules. If you don't have game normally, you can get wasted, then approach girls, because you just don't care. Approaching girls like that shows how it's not a big deal, so you're less stressed even when you're not drunk.