Puberty blockers for example, I’ve known about since the 80s because I I had a childhood friend that was dealing with precocious puberty but we didn’t know it.
He was absolutely miserable. He had horrible mood swings, and get touchy feely with everybody, had awful nightmares.
Then towards the end of the year he was fine
Everybody thought his parents were getting a divorce or something
Years later, bout mid 90s he told us all about it while drinking.
They had him on blockers for a few years and then they took him off somewhere in late Middle School so he could be on track with his peers.
So I Knew by the mid-90s that puberty blockers serve a purpose and they work
That wasn’t the only time but it was the first I remember