Let's be reasonable.
Your muscles and hypertrophied body is your income. Your $$$ earning potential is directly related with your inflated muscles. Doesn't matter if you are a Mr. O contender, budding amateur, Chippendales dancer, or gay bar hustler. You need your appearance to earn your meals.
Now in light of that, would you really be stupid enough to order illegal substances directly to you? Think about it. You eat, sleep, train, inject and show your body. If your body looks like shit, you don't have a "job". If you are in jail, you won't be able to keep that meal ticket of a body you have.
Or you have a professional career with a professional license that could go up in smoke if you get snagged with a felony charge.
So what do you do for your fix? You get someone else to be the fall guy. Sounds like a bitch move but there are plenty of people out there with less to lose than you do and they will do it. So you make the order, get a few things for them in exchange for taking the risk and making the pick up.