If it's just puberty blockers, as I claim in the previous comment, correct. Which is to say, up to the age of 15, there are no permanent changes. From 15 - the point where they start hormone therapy, that's anywhere between 5-10 years into the overall treatment - there are more permanent changes. The two are distinct phases in their transition.
But nothing really life altering. Will the child end up looking different if they de-transition after taking hormones, yes. More breast tissue if they took E, and more muscle definition if they took T. However, these are also body developments that can also happen without human intervention.
I didn't mean to misrepresent your post. It looks like throughout this thread, my original question became distorted from a larger scope to just puberty blockers taken at an early age.
Anyway, aside from effects on bone density, I did find this:
> One of the disadvantages in adolescent girls who have been treated with GnRH analogues at an early age is the possibility of insufficient skin for penile inversion vaginoplasty.
> How Young Is Too Young: Ethical Concerns in Genital Surgery of the Transgender MTF Adolescent
I could be misunderstanding this, but it sounds like there could be lasting effects on penis growth. Wouldn't that make sense, since your body would be getting estrogen during a time where it'd normally be developing in a way where it'd otherwise would be receiving testosterone?
Double check those bone density results, because new research shows they're present before treatment with puberty blockers starts. Some theories are that some children have reduced access to sporting activity.
But nothing really life altering. Will the child end up looking different if they de-transition after taking hormones, yes. More breast tissue if they took E, and more muscle definition if they took T. However, these are also body developments that can also happen without human intervention.