is there any way to stop an amab person's body producing testosterone without an orchiectomy?
Permanently, not that I’m aware of. There is a subset of antiandrogens used in HRT for AMAB people that are called “androgen synthesis inhibitors”; while a lot of these exist, the ones used in this context are gonadotropin-releasing hormone (GnRH) antagonists. These reduce secreted testosterone levels themselves, rather than just blocking androgen receptors like other antiandrogens do; they’re also used in treating prostate cancer, and are sometimes referred to in medical literature as “chemical castration”, which is... a complicated term with a lot of history behind it that I would advise immense caution for practically every trigger under the sun if you decide to look it up.
The reason that androgen receptor inhibitors are more commonly used in HRT for AMAB people is because the most commonly available GnRH antagonist, Lupron (which you might be familiar with if you’ve read about puberty blockers!), will also reduce the production of estradiol. AR inhibitors don’t do this, they just prevent your body from hearing the signals that testosterone is sending and trick it into thinking that there’s less of it around in the first place.
- Mod Wolf