Puberty blockers are reversible by just going off them. Do you get that?
That's a myth, and a dangerous one.
But for the sake of discussion, let's say that that PBs were safe and reversible. The reality is that once you start a kid on PBs, they're extremely likely to continue on to hormones, and they're unlikely to grow out of GD and resolve to being gay.
So once you start in with PBs, GD kids who were probably just gay will not get the chance to let nature take it's course.
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To me, if you're a parent with a GD kid you have several options:
1 - ignore it - that seems like a bad option
2 - use only talk therapy and see if the GD resolves without drugs. For kids who resolve to being gay, this seems like the best option.
3 - use only talk therapy and delay drugs until they're older. The downside here is that if the kid IS trans, delaying drugs will allow their body to change in ways they find uncomfortable.
4 - use GAC, which typically means drugs early on. IF (and that's a big IF), the kid is actually trans, then this might be the best option. BUT, you ARE inflicting a lifetime of medical treatments on this kid. These drugs have serious, lifetime side effects, including lack of sexual function. So GAC often results in a lifetime with no orgasms - a high price.
With most non-life-threatening medical situations for which a diagnosis is not possible, doctors shy away from extreme measures like GAC.
So to ignore option 2 seems morally wrong to me. Are trans kids more important than gay kids? Not to me they're not.