chemical castration in Halacha

If the chemical castration is irreversible – then it is not allowed (except for life-threatening situations, Pikuach Nefesh)
If the chemical castration is reversible – then it is important to distinguish between cases of consent or lack of consent on the part of the castrated.
The reason for this is that there are certain medical risks so that they cannot be forced on a person.
(The prevention of harm done by a pedophile can be achieved by closed institutionalization).