Thanks Alis. Interesting interview with Andy as well.
I agree that the tennis authorities need to get their act together and increase the number of tests, but at the same time the onus is on all players, no matter what their ranking, to familiarise themselves with the Rules - to which end they receive an abridged version of them which they're supposed to carry with them at all times - so if they fail to do this then they should get no sympathy when caught out.
There's no excuse either for not reading labels properly when it comes to over the counter purchases. The UK has the highest standard of drug control in the world, while other countries are more lax with some more lax than others, the Far East in particular, and if there's something they're not sure about they should seek the pharmacist's advice. If that doesn't clarify matters then don't buy the product! As a diabetic I have to be very careful what I take because some things can interfere with blood sugar levels, so if I'm left in any doubt at all, that's it.
Also if players are taking any medication or supplements, whether prescribed or bought over the counter, while they're in competition, they have a duty to inform the tournament doctor and thereby check whether or not they contain a substance on the banned list.