No real side effects besides when I do cycle I notice acne and i normally have a pretty clear complexion(sp?) and sometimes it feels like bloating but I dunno what that is from. Right now I am at about 203 and I actually haven't taken them for a few months as I'm now trying to do more cardio and get rid of some beer gut When I'm in a bulking phase though I will probably take them again. I will probably stop once I hit late 20s........I never do a full 6 week cycle because the following weeks are such a drop in performance that its depressing. I usually only do 3-4 weeks because I still get good gains but then it doesn't decrease as much.