There was a dose response study in normal men correlating testosterone dosage and lean body mass, here is Bryan's take on said study:
"We know for sure it is up to 600 mg/week without showing any signs of diminishing returns so I estimate it would continue until about 1,000 mg/wk, but Iím speculating on that figure. Still, from the research we have, you get (all things being equal) about 3 pounds (1.5 kg) of fat free mass for every 100 mg of testosterone per week up to at least 600 mg/week over the course of about 16 weeks of use. And like I said, the dose response showed no signs of attenuation, it was linear through 600 mg/week"
So hows does this researcher/doctor come to such different conclusions regarding the same results?
"for each +1% in lean mass you would have to increase your testosterone level by >27% - and maintain that over a time-course of 20 weeks! And as if that was not enough, even if you would survive boosting your levels into the >+400% zone, you should be aware that the slope will level out and you will probably need another +100% to make the +1% addition in lean mass. "
Here's the full study in question.