http://www.uk-muscle.co.uk/steroid-test ... rview.html
SPIEGEL: Do you have any other secrets?
Heredia: Oh yes, of course. There are tablets for the kidneys that block the metabolites of steroids, so when athletes give a urine sample, they donít excrete the metabolites and thus test negative. Or there is an enzyme that slowly consumes proteins - epo has protein structures, and the enzyme thus ensures that the B sample of the doping test has a completely different value than the A sample. Then there are chemicals that you take a couple of hours before the race that prevent acidification in the muscles. Together with epo they are an absolute miracle. Iíve created 20 different drugs that are still undetectable for the doping testers.