"Chemical castration" is not an event, it's an ongoing process of injecting the offender with the female hormone progestin. If the injections are discontinued, theoretically the process will end and normal function of the testes will return.
“... it is injecting the offender with the female hormone progestin”.
So if a person injected themselves with testosterone... would that reverse the chemical castration?
So all these creeps need to do is just stop getting injections? It doesn’t sound permanent enough.