I dont know about that, but I remember I once went out with a guy who had smoked alot of marijuana and some other drugs and he always had a real hard time getting to ejaculate-it took him ages. i dunno, i think maybe it can do some deterance of growth but im not sure.
I dunno if it will reduce testosterone or not, but I knew a guy who had smoked marijuana heavily since before he was in his teens and he seemed to have no problems in the size department. He was well above average, in fact. Of course, one could suspect that if he hadn't smoked, he could have ended up with a few more inches per his genetics, but there's really no proof either way, I don't think.
Most depressants, like marijuana and alcohol will inhibit your ability to sustain an erection and achieve orgasm. I've never heard anything about size.
It is much harder to concentrate due to the chemical changes. They have done studies at my school where they have introduced various drugs like marijuana, LSD, etc. to spiders and they produced highly irregular web structure.
So.. if you want to produce a highly irregular web structure, or really frustrate your partner, do drugs. Don't listen to the potheads.
Crimson, I see that you have bought into the government's propaganda war against cannabis without researching the issue yourself. First off, marijuana is not a depressant...you are thinking of alcohol. Secondly, there is absolutely no evidence to prove that marijuana use, in any way, impairs sexual function or body development. Thirdly, what does a spider on lsd spinning **** have to do with a human's penis growth. Your opinion is based on myths and lies. Leave those potheads alone....they are having great sex despite what you may "think".