. If you go back to Arnold's time sure they had drugs but most took them under medical supervision and thus few got side effects. Compare that to what is happening today. .
The medical supervision wasn't worth much, the docs didn't know what they were doing. They gave Deca and Dbol to kids - for example The Coach started by 15 via prescription.
Bodybuilding is experimental, even a doc can't predict what will happen with the combos of drugs used.
Many gurus do try to limit sides by having blood work done, keeping tabs on BP etc