Gadolhadorah, I would like you to read this, and tell me if you believe recreational weed is ok (where legal).
As for medicinal, no hechsher is required anyhow, as far as the psak I am aware of (also discussed in the link i believe).
I have never started a thread, but if i ever do, I don’t want it to be on recreational drugs. I am not a fan. Not judging others though.