It's a fact of life that some GPs are better than others.
I realise this might not seem entirely connected. I don't mean to hijack your topic, hopefully it might contribute something to the discussion.
I've had depression for most of my life. It has eased, somewhat, since I was 40. But getting any support has been a nightmare.
Its nature is/was that I try various coping strategies, but when it becomes acute I have ask for some help.
In my early 30s, I went to see a Dr with whom I had previously gotten on quite well. He had always been really friendly and shown a genuine interest. He had a reputation in the area, a very rural community, for being friendly, easy going and knowledgeable.
Anyway, he started treating me with a particular medicine which eventually had a significantly beneficial effect. For those who've ever had depression, they will know what I mean.
After a few months, he made a suggestion to me, which I knew, from previous experience, wouldn't work for me.
He immediately went to check my case notes. After at least 15 minutes, he returned with an entirely changed personality. It was quite weird. He looked the same of course, but sounded and acted like a completely different person. He virtually (in that he strongly hinted) asked me to leave.
I still don't know what that was all about. His manner made it clear that there would be no discussion.
Now as I said, deepest apologies if this seems like an irrelevant hijacking of your thread. I just don't think we can necessarily assume that there is any right or wrong way to approach these people. If they reject you, as this one seems to have done to your friend, then it might be wisest to find a different strategy.
I really wish I could make suggestions. Sadly I'm sure you will appreciate, it's so much more complicated than that. What I do know is, these people's objective is their own egos. They hate failure simply because it reflects badly upon them, in their eyes.
They will reject anything they see as being problematic simply because they fear the consequences of failure to their self esteem.
Sadly, your friend's rejection will now be a matter of record. It is unlikely another GP will take the matter up, because to do so will not just be taking a chance of this issue, it might equally offend the current GP.
I will caution you about seeking black market hormones, but it is cases like these where we can understand why some might think about it. The term, Black Market, in this instance, give a whole new light to black markets in general. We generally assume that people go to the black market to indulge illegal activities. In the case of your friend, she is simply trying to manage her own life. But the down side is the lack of quality control, not to mention the need for continual monitoring, especially of your kidney function. Killing your kidnesy is not a good idea, as I'm sure you will appreciate.
As I said, you need to look at alternatives. Not be single minded here.
The medical approach seems to be shut. Baring something quite major, that door seems to be shut.
You should know that there are numerous others in our situation. Not just transgender, but other conditions which make adjustment difficult. I suggest that, most get knocked back by GPs. The success stories we see here, for example, are the tip of the iceberg, compared to the vast majority who are pushed away.
I long ago realised that a lot of medicine is a bit like those adverts for the lottery. If you believe them all you do is buy a tcket and become rich. (And strangely very happy!!). The reality, in that instance as well as this, as we all know, is very different.
I so wish I could be more helpful.