Unless you have concrete proof that Regina is on drugs there isn't anything one can do about it, regardless of how much folks might suspect her based on her actions, personality, perception, etc. Unless someone is willing to swear to her guilt and has material proof, she is not going to get nailed and nor are those who cover-up for her. Naturally that is going to invite cynicism but that's how it would stack up in a court of law. Like her or not, she is innocent until proven guilty, even if 75% of the casual observers believe in their gut Regina at 39 is using drugs.
If we're going to talk about 39-year-olds kicking ass, what about Colleen De Reuck? It can happen, but the odds are absurd.
One of the problems with putting stock in drug-testing as a measure of being clean is that it's thoroughly lacking in comprehensiveness. According to this site's favorite whipping boy (CU coach Mark Wetmore) in 1998, there are roughly 70 manufactured substances on the USATF and IAAF banned list with testosterone derivatives. However, there are probably one thousand testosterone-derivative-based substances available to the public. Thousands of substances exist, which if tested would probably be banned, but the testing has failed to reach that level of sophistication.
The second problem is more widely known. Druggies are, scientifically speaking, way ahead of the drug-testing process. The testing process might be able to catch one-third of the cheats out there. There are so many ways to mask a positive result or simply not produce one. Think about it. How many world TnF records or even top five times do you really trust? IMO less than half.
Thirdly and fourth, the drug-testing process is flawed and things are more complex than they might appear. The best example: When Uta Pippig was "busted" and punished by the German federation for having too high of a testosterone to epitestosterone ratio (at 11:1, well over the IAAF legal limit of 6:1), anyone not looking closely would have assumed she was dirty and they do so to this day.
The signs of implied guilt were all there: Pippig is a former East German, saddled with a secretive, overly possessive lover/coach, was running 180 MPW, etc. But when Uta was tested, no one mentioned that her testosterone level was the second-lowest out of 16 females tested. And her EPItestosterone level, however, was comparable to that of an 85-year-old woman. (This information was verified by her chiropractor Dr. Doug Terry of Boulder and his colleague at the Harvard Medical School).
So in Uta Pippig's case, she there is a good chance she wasn't guilty, she was just totally wrecked. Her career might have been over regardless. But as it worked out, the testing mechanism was flawed and failed to acknowledge her abnormally low T/EPIT readings, and Uta got screwed by the Germans who didn't want her to abandon them for US citizenship.