The use of caffeine tablets to enhance player performance in Australian rugby went beyond the Wallabies, Australian Rugby Union chief executive Gary Flowers has admitted.

Flowers said a few under-age national players, such as those from the Australian under-19 team, were also using the stimulant, adding the ARU considered the use of caffeine tablets "appropriate" in a professional sporting environment.

Flowers also supported the forthright comments made by Wallabies captain George Gregan.

"As far as the professional environment goes, performance enhancing supplements are part of the professional game and we don't see a problem with it," Flowers said.

"As far as children are concerned, there are obviously a whole bunch of training regimes and supplements that are not suitable for kids, and (caffeine tablets) fall into that category. I think the message is certainly one of education. It's about this being something that is only suitable for the professional environment."

That "professional environment" included sides as young as the national under-19 side, which came under the banner of the ARU.

While the use of caffeine tablets was not a team policy in any ARU side, there were no guidelines preventing individuals from taking the stimulant.

"I think there are a couple of players (in national age teams) that may be taking caffeine tablets, but I'm not aware of any further use," Flowers said.

"In terms of those younger age teams, when they come under the ARU, they are part of a professional environment and they would be supervised by professional coaching staff that would be involved with their training and dietary supplements as is appropriate."

Gregan became the latest high-profile sports star to acknowledge using caffeine tablets, saying he and many Wallaby teammates took the pills before matches.

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