Hmm. this is a tough question and one which I can't fully answer, but I have a few things to offer. in most martial arts, there is some kind of an expectation of respect, given and received, and honor. if you would feel comfortable with your sensei knowing, for example, that you use prohormones then maybe it can be something you can use in good conscience. that's what i would say. but strictly speaking, MMA has gone beyond the scope of what is a martial art and turned into more of an exhibition (at least it feels that way to me), and i'm sure many more guys than you know use PEDs. i would probably say it's about the same number that take them in any local gym. maybe the organization that puts on the local bouts has some kind of rule book. if PEDs are banned, whether you're tested or not, then it is unethical to use them.