Wait so now steroids  DO create muscle mass...... because I could have sworn you said the opposite and provided literature that indicated that. 
Why has your position  changed?
Was Casey still natural when Arthur Jones conducted  workout  experiments on him? 
Epic trolling  junior.
No, elevation of a man's testosterone level above a healthy range (approx. 300-800ng/dl) will 
NOT increase his results as a results of resistance training.  
Ethical medical use of exogenous testosterone in cases such as hypo gonadism, delayed puberty or sickness/injury is what these type drugs are intended for & the only rationale use of.
When Casey Viator was employed at Nautilus Sports Medicine Inc. he did not use steroids in any capacity.  When he moved to So Cal. w/ Mentzer he very much did abuse steroids & they ruined his career & health as well the Mentzer Bros. & countless other misguided individuals.