Is It Time for T?

Beyond those simple facts the shadows begin. Norms for other physiological measures, such as blood pressure, have been well characterized over the years, but testosterone levels tend to have a lot more individual variation. The standard range turns out to be somewhere between a bloodstream concentration of 300 and 1,000 ng/dl. The fact that two individuals can share the same testosterone ?profile? (sex-drive, mood, energy etc.) but with a 100 percent difference in testosterone levels?one man at 400 ng/dl, the other at 800 ng/dl?shows how crude the measure can be. One might look at ?free testosterone? instead, to see what tiny fraction of total testosterone is not bound to blood proteins, and therefore chemically active and free. But this is hard to gauge with precision, and therefore not recommended as a screening blood test.

march madness scores doonesbury mike adams daughtry padma lakshmi ides of march lakers trade