This weekend will see the introduction of drug testing throughout Gaelic games. The All-Ireland semi-finals had always been the target date for the introduction of the anti-doping programme accepted by last October's special GAA congress and signed up to nearly three weeks ago.

The programme was drawn up by the Irish Sports Council (ISC), and although it comes into operation at the weekend, the ISC will determine when precisely testing will begin.

"This is the norm for all sports," said Dr Una May, acting manager of the ISC Anti-doping Unit. "We agreed with the GAA that testing would begin once the championships reached All-Ireland semi-final stage. It is a matter for the ISC to determine the game at which the first tests will be taken." Wexford hurlers play Tipperary this Sunday in the first of this summer's All-Ireland semi-finals.

On Saturday an education forum will be held in Croke Park. According to the ISC, "its purpose is to inform relevant administrators of operational matters, such as prohibited substances, procedures for dealing with permitted medications, sample collection procedures and results management."

This might appear a little late on the weekend of the programme's introduction, but in recent weeks and months the GAA have undertaken a major educational programme in advance of the tests.

The most difficult issue is expected to be that of dietary supplements, which have been at the centre of the recent nandralone controversy in athletics.

As one GAA official put it: "If you want to produce foodstuffs you're subject to regulation, if you want to produce medicine you're subject to regulation, but anyone can produce a dietary supplement. Getting guys up to speed on this sort of thing is vital. It would be terrible if anyone was suspended for inadvertent use of a banned substance.

"Any positive test can be for one of three reasons: the substance has been taken inadvertently, for medication or in order to enhance performance."

Some concerns have been expressed, in the context of the GAA's amateurism, about the dangers of players testing positive for recreational drugs and the consequences for their private life or career. Alcohol and cannabis are not proscribed, although the latter is in breach of the Misuse of Drugs Act. Cocaine and other stimulants are on the banned list.

Dr Conor O'Brien, chairman of the ISC Anti-Doping Committee, emphasised the importance of testing.

"The importance of an anti-doping programme is not just to make sport fair, but also safe for its athletes."