system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are steroids bad to the body if they enhance physical capabilities and why can't we nullify those side effects?
gpt
The body works to regulate hormones by feedback. If it detects too much of X hormone, it won't produce it anymore (a problem whether one is using, or stopping use).

ELI5: That's why ze balls shrink sometimes.