Tyrone star Sean Cavanagh has said he fears players could be taking illicit performance-enhancing substances without even knowing it.
The 33-year-old backed the GAA's decision to start blood testing players this year, but warned of a culture of leaning on supplements and shakes that could lead some down a dangerous road.
"You know, five, six, seven, eight years ago, whenever we were tested, 10 years ago, the worst thing you could probably fall foul of is a dodgy Lemsip," Cavanagh told the Irish Independent.
"Nowadays there's that much proteins, branched chain amino acids - I don't even understand half the stuff the boys are taking to be honest.
"I'd say there's probably a reasonable chance that some guys are maybe [on performance-enhancing drugs].
"A lot of guys just aren't educated enough to know what they can and can't take."
"I'm not all that into it. I'm still stuck in the Tracker bar and Jaffa Cake era, 10 years ago! Look, some guys are hugely into it nowadays so I'd say there probably is a chance, whether purposely or not, that there probably are guys that are playing that have something in the system that shouldn't be there. That's just a fact of life.
"I suppose there's that much available in terms of supplements and a lot of guys just aren't educated enough to know what they can and can't take. There's that many things on the internet that are saying 'batch tested' and what not but it's a complete minefield at the moment."
It was announced before Christmas that blood and urine testing for players will be introduced for the first time as part of the 2016 Anti-Doping programme rolled out by Sport Ireland.
Cavanagh admitted he believes some players are "taking the chance" when it comes to doping as he revealed he's been tested 10 to 15 times throughout his career.
"I suppose you have to recognise that there is a risk there and guys are taking that chance. I have no doubt there are players out there who are probably taking the chance."