Hi Hurdity, yes I agree. All medical advice should be evidence-based.
I too thought the consultant must have a reason to say it, and that's why I asked for more information.
I have the "it's tachyphylaxis" in writing from one of the authors of the original papers you refer to. This was at 500 pmol/l. The other author told me 'tachyphylaxis - it doesn't exist'.
I've found it helpful to reflect on the definition of tachyphylaxis "rapidly diminishing response to successive doses of a drug, rendering it less effective".
And I've also seen that tachyphylaxis isn't limited to estrogen. People using other drugs including anti-depressants can experience tachyphylaxis. In this case it is well-documented. e.g.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008298/Yes, those are very good questions about the incidence, and why doesn't everyone get it. Not everyone who takes an AD gets tachyphylaxis either (genetic differences? other factors? and because they are lucky - this has wrecked my life)
Yes I thought that about exogenous estrogen too. There's no answer I can find, but yes I agree with you.
Because I've been so badly affected, I am obviously deeply emotionally invested in this. I am very confused and frustrated by the lack of consensus, evidence and science around this issue.
But I recognise that I need to find a way to accept what's happened as otherwise I won't be able to live a fulfilling life from now on. But it is extremely hard when it affects every aspect of my life so negatively. I know I'm not the only one affected - others here are suffering too xxx