Dude.... people use sterioids because they max out their bodys potential to gain muscle. One can only gain so much muscle due to genetics, weather your body type is an ectomorph, endomorph, or a mesomorph. Thats where steroids come into play.
However.... your bodys natural ability to cut, unless you are hinderd buy a disease or an other disorder, is endless.
What instantmuscle said is correct. DIET...... and cardio is the key to cutting and unless you are competing there is no reason in my opion to use substances to cut,becuase lets face it, you dont need a "drug" or what ever to do that,so dont do it. I would be willing to argue anyone that stated otherwise.
If you do it naturaly it builds your character as a bodybuilder, chems, man anyone can do that.
Might, not mean much, just my two cents.