There was an (possibly online?) article written by a guy who was taking drugs in order to see what effect they would have on ana average club cyclist riding long distance sportives like Lige-Bastogne-Liege, think he even did one as stoker on a Tandem.
IIRC he found the drugs really hard to come by, no doctor would touch him, including the ‘usual suspects’. Think he was doing stuff like injecting testosterone then it was topped up via patches, he was using steroids and EPO too IIRC.
He was quite open about it and pointed out that none of the events entered as part of the experiment had prize money or winners so he wasn’t taking something unfairly from another competitor, just doing it to see what the difference was (quite big IIRC).