There is a difference between a bit of hair thinning with age and female pattern baldness - which is called androgenic alopecia. It is related to testosterone (DHT). The clue is in the name...
It is also very much the same issue which can causs hair loss through testosterone replacement for some women.
"Estrogen can support hair growth but as levels decline during menopause so can hair growth, and there can be shrinkage in hair follicles. For some women, the decline in estrogen means the balance between estrogen and androgen (a group of sex hormones including testosterone and DHT) is altered, which can worsen female pattern hair loss."
www.drlouisenewson.co.uk/knowledge/testosterone-and-hair-during-menopause
Hence why I said- it won't stop me trying testosterone as I am on a high dose of estrogen, but I will be wary of side effects because in some women testosterone replacement absolutely can and does cause severe hair loss. It's a very individual decision about whether to still use testosterone, but it should be an informed decision.
My mum very suddenly went almost completely bald in just the same way a man would - receeded hairline, large circular bald area covering the entire top of the head, she's very upset about it. I absolutely understand why a GP would be wary of accidentally inflicting that on a woman in her 40s/50s.
The fact its just a small blob of something doesn't matter one bit. A small blob of cyanide will kill you. We are all different and what's helpful for some women, can cause significant, permanent side effects for others. A small blob of estrogen gel causes severe migraines for me - for some women it's absolutely fine and helpful.
I'm not a GP who is reluctant to hand out prescriptions, I'm a woman who would very much like to try testosterone (and have been told by my GP she'd be happy for me to do so), but I also understand the relationship between using testosterone replacement and my own genetic predisposition to androgenic alopecia.
You can deny it all you want, but there is lots of evidence that using the standard dose of testosterone used in the correct way can cause excessive hair loss in some women, which is why it is a named side effect and not a theoretical risk. Side effects don't happen to everyone, but there are also lots of women on forums who have to stop using testosterone because it causes them hair loss. It's not just some made up thing by the patriarchy who only care about whether men are getting laid. It's an actual side effect of a drug for some women, just like estrogen can and does cause migraine in some women.
I think women absolutely should have a full understanding of the potential side effects so they can make an informed decision about their own medical care.