Hi Jbeck, the steroids such as those taken by bodybuilders and athletes we actually produce in our bodies, testosterone we make inside our own body and we use it very effectively. If we are to add more in, as bodybuilders and athletes do then we can do serious damage as we disturb the delicate balance within our bodies. As they pass through our body, we process them in our liver and can cause severe liver damage. And as they are taken to get bigger muscles, our heart is also a muscle and if we get bigger arms then we may also get a bigger heart and this puts huge strain on our arteries and veins and can lead to quite often heart attacks and premature death! So to answer your equation, yes-they can have serious long term side affects.