AFL medical officer Dr Peter Harcourt made the revelation to doctors, physiotherapists and sports scientists during Grand Final week.
He was quoting from an AFL survey - conducted following the release of the Australian Crime Commission's Drugs in Sport report - which also revealed that club documentation of player supplement use was "inadequate".
As a result, significant changes have been made to the AFL's anti-dopingcode.
The supplements survey also found that 12 clubs conducted programs with medium or high levels of supplement use and lacked "a single point of accountability".
And there was also an inappropriate definition of supplements and the selection process of support personnel was flawed.
In a year of controversy that saw Essendon jettisoned from the finals and its coach James Hird suspended for the club's supplements program, St Kilda forward Ahmed Saad also fell into the spotlight after he inadvertently consumed a substance registered on the AFL's Anti-Doping banned list.
Saad began a provisional suspension in August after failing a post-match drug test in July.
The new legislation establishes a catalogue of AFL Prohibited Treatments and AFL Controlled Treatments, with a comprehensive list to be completed before the start of the 2014 season.
The AFL will also consider prohibiting specific providers of treatments to ensure safe practice and protect the game from the influence of organised crime.
AFL integrity services manager Brett Clothier said the revised AFL Code will go "above and beyond the WADA code".
AFL Prohibited Treatments, in addition to the WADA list, cannot be used at any time and will include any treatment that is not TGA approved.
AFL Controlled Treatments can be used, but require written approval from a club doctor.
Clubs must also maintain secure storage of controlled substances and record any controlled treatments in an AFL register.
The new AFL Anti-Doping Code includes a no-needles policy, which means doctors may possess needles but can only inject players when it is necessary to treat a legitimate medical condition.
AFL chief medical officer Dr Peter Harcourt, who led the survey, said the year's events should be used as an "opportunity for the industry" to establish best medical practice and responsible club management.
The AFL is currently engaging clubs and other stakeholders on how the changes to the AFL Anti-Doping code will work in practice.