Haha you got rickrolld...just as we all have aat one point.
You can kinda tell when he did start juicing. I saw his posing routine from '95 I think it was. He still looked big, but not as dense if you will & he also had what I call a true vaccum stomach. Then fastfoward tp '96-'98 he still looks lean, but much harder, fuller, & no more vaccum stomach.
I also found it odd for some reason that Flex introduced him to steroids...but whatever though.
Dude's still my all-time bodybuilding idol. If I can be half as big as him...
The gut is actually caused by HGH, not steroid use. If you check out some of the old school bodybuilders like Arnold you'll see that they all have tiny waists and they were all juicing.
I believe that Ronnie made it pro without steroids, that's how he ended up becoming Mr Olympia. It's like that one powerlifter (can't remember his name) said, steroids are like your ace card. The longer you can hold off using them the more successful you'll be. He said something along the lines of:
If you need them in high school, you won't be playing in college. If you need them in college, you most likely won't go pro. If you use them after you've established your career as a pro, you'll add a few million dollars to your salary.
^This is of course referring to pro athletes, not bodybuilders, but the same principle applies to both worlds.