Yes, they make you more PRONE to be aggressive, but it is nothing that is uncontrollable. Alot of people on this board will say its a myth and that its just you being an asshole, using it as an excuse, etc. Unfortunately, many of these people are just supporting these substances because they use them themselves and don't want to admit to any potential problems/sides with them. Its like asking a pothead if weed is bad for you (it really isn't that bad), they'll tell you absolutely no way is it bad for you, but the fact is that smoking anything, whether its tobacco or dried up carrots, has the potential to be caricinogenic. Sorry fellas, but there are side effects to the juice and aggressiveness and irritabilty are some of them. This fact has been proven in numerous medical studies....fuckin Hitler gave testosterone to his soldiers to make them fearless and aggressive. But these sides are really no big deal (at least for me), as long as you have some self control. They're not going to turn you into a raging beast that beats people senseless for looking at them or walks along all day with a crazy look in their eye. The best example I can give is when I did my first cycle. I didn't get pissed off for no reason, but there were a couple of guys at work that irritated me because they were assholes who somehow got the notion they were in charge of me. I never really said much because it was a summer job and I wanted to keep the peace...but once I went on the juice, no more. Within a week I had told them both what I thought about them and that they can kiss my ass. Like I said, I didn't get angry for no reason, but the shit that did make me angry for legitamate reasons didn't fly anymore.