I couldn't disagree with Dana White's point nor his wording more. First of all, if as Dana puts it, "every guy's testosterone starts to drop as they get older," than isn't THAT "normal?" Having a lower testosterone level at 35 than 19 is normal. Artifically enhancing it back is not.
Plus, where does one draw the line? Humans produce growth hormones when they're younger, and those taper off to some degree as we get older. Why not start taking HGH to get those levels back? I mean c'mon. There's more holes in that argument than swiss cheese.
Everyone gets older, athletes included. Artificially extending a competitor's career life is still just that: artificial. To me it defeats a major purpose of martial arts and taints the sport. My 2 cents.