MONTREAL - The head of the World Anti-Doping Agency acknowledged that Viagra is being examined for its potential use as a performance-enhancing drug.

WADA is currently sponsoring a study to determine whether the blue, diamond-shaped pill, widely associated with treating sexual dysfunction in men, may be used for a competitive advantage in sports, according to the New York Times.

"It's amazing the interest that particular drug does attract," WADA president John Fahey said Sunday following a board meeting. "I can simply say this, there have been statements to suggest that it is performance-enhancing -- that is being evaluated."

Viagra, or sildenafil citrate, works by supressing an enzyme that regulates blood flow and allows vessels to relax and widen. It also is used to treat pulmonary hypertension by relaxing the arterial wall.

In the case of athletes, increased cardiac output and more efficient transport of oxygenated fuel to the muscles can enhance endurance.

"It is under review, no decision has been made and before any changes occur -- as I'm sure you appreciate -- to the prohibited list, it has to be a rigorous examination that allows the committee to make a recommendation," Fahey said. "It's not being ignored, but there has been no decision on it and nor would I suggest that you should interpret what I've just said as a likelihood that there will be either a positive or a negative decision when the examination is ultimately concluded."

WADA is also giving stragglers an extended opportunity to get inline with its efforts to root out drug cheats. Fahey, though, made it clear that the global organization's decision to wait another six months before making any declaration of non-compliance with the World Anti-Doping Code is the only extension that will be made.

"I have to say that if there should be any further extensions, I would be very, very disappointed, and I will certainly be arguing strongly against them," Fahey said. "Yes, it's six more months, but in the meantime I'm confident we'll have a lot more that are compliant as the result of this extension, and that's the important thing."

Fahey declined to name any of the sports or international federations that have been delinquent in enforcing the current anti-doping code, which went into effect in January 2004.

"The weighting's heavily, at the moment, with those nations that are very limited in the context of capacity based upon resources," Fahey said. "That's another reason and an argument that was put in the discussion that we should help them rather than just simply say, 'Look, you had your chance and you didn't make it."'

He added that WADA does not have a mandate to apply any sanctions for non-compliance with the code.

"That is a matter for the international federations, it's a matter for the International Olympic Committee," Fahey said. "All we do is report. What they do after that is their business."

A revised code set to take effect on Jan. 1, 2009, will offer more flexibility in applying sanctions, with increases possible under "aggravating circumstances" while penalties may be lessened in other situations, such as an athlete who can clearly prove that a forbidden substance was not intended to enhance performance.

Fahey thanked the French government for seconding an officer to act as a liaison between WADA and Lyons-based Interpol.

"That officer will be the link between the governments of the world and their enforcement agencies and the insidious development of the substances that we are endeavouring to stamp out in sport," Fahey said. "I believe we will see some significant outcomes there as a result in the years ahead."