I do recall C.J. say that he was working Drago's corner for that fight and did mention something about the commission being unfair and against insulin shots.
Bob Hazelton. He fought George Foreman in 1969. Hazelton was a tall but fairly scrawny heavyweight. Foreman stopped him in the first. Hazelton quit boxing. Two years later, in 1971, Hazelton says he began taking steroids. In 1972, he resumed his boxing career. But they didn't seem to help. In 1978, a 40-year-old former light heavyweight champ Bob Foster knocked him out in two. Here is Hazelton's story. It didn't end well. https://www.chicagotribune.com/news/ct-xpm-1989-01-01-8902220419-story.html Muhammad Ali practically overdosed on diuretics before the Holmes fight in 1980. There are countless articles and books on that topic. Frans Botha was the first I recall who lost his title because he tested positive for steroids after beating Axel Shulz for the vacant IBF heavyweight title in 1995. Vitali Klitschcko was banned from the Ukrainian Olympic boxing team for testing positive for steroids in 1996. (Wlad took his place and won the gold medal.)
Most of them are Americans, Mexicans and some Eastern Europeans/ Western Europeans. This is the facts.
north dallas forty came out in 78 and heavily insinuated roids were almost universal at that point. nothing has changed since.
Lol! I did a super quick Google search for it when I was at lunch... wikipedia has a list of supposedly all the boxers that have popped or admitted to taking PEDs... but there didn't seem to be anyone pre 80s that I could tell... so not sure how complete the list is. Someone could just go down that list though and find the earliest failed test. I didn't cite it here tho because I dont have a ton of confidence in its completeness.
Doping goes way back in sport. You might want to narrow that down unless you wanna do a historical piece? Doping in cycling dates back to the very early 1900s. Back then guys were using craxy stuff like nitroglycerine to get the heart pumping, cocaine to numb the pain, and of course the good old trusted alcohol. They were boozing it up in the alps way back. for ex. https://sportsanddrugs.procon.org/view.timeline.php?timelineID=000017