What options are there for transgender girls to block puberty, in the absence of GnRHa puberty blockers?

The Australian Treatment Guidelines recommend two medicines that prevent the actions of testosterone if you can’t use the GnRHa puberty blockers:

1. Spironolactone: 100mg oral daily, increasing to up to 200mg oral twice daily as required

2. Cyproterone acetate: 12.5-50mg oral daily