THERE is "no magic potion or magic pill" that makes athletes better at sport, according to leading AFL medico Dr Peter Larkins.

On a day that saw Essendon skipper Jobe Watson admit he was still concerned his teammates could receive infraction notices from the Australian Sports Anti-Doping Agency, the NRL announced proposed penalties for the Cronulla Sharks, who have been embroiled in their own supplements saga this year.

Bombers seek clarity from ASADA and AFL

The substances that have been central to both cases are not only potentially outside the rules, but their performance isn't proven, according to Larkins.

"Players are presumably being told they're going to play better if they take these products so they're presumably designed, at least in the player's mind, to have an effect on muscles or recovery in some way," Larkins told ABC's 7.30.

Click here for our full coverage of the Essendon supplements scandal


"But if you're saying there are well-established clinical trials and safety profiles for a lot of these peptide hormones, then clearly there aren't.

"There's no magic potion or magic pill that's going to make you play sport better. It certainly doesn't come in a needle."

ASADA's investigation into Essendon's supplements program is ongoing, with infraction notices still possible if Bombers players are found to have taken banned substances.

Outgoing World Anti-Doping Agency boss John Fahey last week said he believed it was "only a matter of when" players would face charges, before later saying that had been a long-held belief not based on detail.

Larkins called for a return to basics in the management of elite athletes.

"We've got to make sure that player welfare and player preparation is in the hands of some experienced people who can use clinical guidelines and know about player safety," he said.


Twitter: @AFL_Nathan