> anger and other undesirable effects.

"other" could mean these from the linked article:

> The growing literature on androgenic anabolic steroid (AAS) usage suggests that some users can develop bouts of aggression known as steroid rage, mood disturbance, hypomania, irritability, and depressive episodes (9–15).

Whenever I think about ourselves, I think from an evolutionary perspective. All of the mentioned effects exist in species other than humans. I can list several reasons why the behaviors could be considered desirable.

Also note, the article says the only significantly increased emotion was anger hostility. Why does anger exist?