Before I leave the bullshit below I want to say I'm not a scientist.
Would adrenaline not be fast acting? It seems like a Wile E. Coyote setup. You inject the gorilla with adrenaline and then get ripped apart as the ex just meep meeps through the window.
theoretically the gorilla could realize that his ex was the real alpha of this situation.
the gorilla would then become the victim faster than he could beat his own chest.
the ex's abuse towards this already abused yet jacked gorilla could also theoretically make a situation where the gorilla goes back to his gym-house to find OP and beat his ass for putting him through all that shit for nothing.