In reply to Sleepy_trucker:
> What is it exactly?
>
> I ask as my brother's been taking it for a while now (maybe 6mths). In my opinion he's changed - he's become quite arrogant and selfish. I've been wondering if its full of testosterone?
>
> He's also very defensive of it - like the druggy who's convinced the stuff's doing no harm and won't listen to anyone who says otherwise.
>
> To be perfectly honest, I'm worried about him - I'd like to see him back to the person he used to be. (Might be nothing to do with the creatine of course).
If he's taking protein powder with creatine in it then it may also contain aspartic acid which is a naturally occurring amino acid that stimulates testosterone production in the body. Creatine also occurs naturally, in meat.
I wouldn't label him a 'druggy' for taking legal supplements though. To get the same amount of protein and creatine as in a typical protein drink he'd need to eat 2 or 3 whole chickens a day at least if not more!