The progesterone wars (the ongoing debate between transfem patients and cis doctors about whether progesterone should be used in transfem HRT) are interesting to me, because I don't think the debate is actually about what either side says, and perhaps even thinks, it's about

In short, stereotypically, trans women want progesterone because it's supposed to improve breast development. Doctors don't want to give it to us because it's supposed to increase risk of systemic cardiovascular disease and breast cancer.

The empirical evidence that progesterone improves breast development is weak. However, there is evidence that a mechanism exists for it. Also, nobody has actually bothered checking whether it works or not since Prior et al. (1989), 33 years ago, 5 years before I was born.

The empirical evidence that progestogens increase the risk of cardiovascular disease and breast cancer looks pretty strong at first glance — it's based on the hormone therapy arm of the US WHI study, which did find increased risk of those things associated with progestogens.

There are probably a few things pissing people off.

1. It's not clear that the WHI study is even applicable. The study cohort had a mean age of 63.3 years (which is roughly the *life expectancy* of trans women) and were postmenopausal (not a concept applicable to most transfems)

The study cohort were taking conjugated equine estrogens (Premarin) plus medroxyprogesterone acetate (Provera), both of which have worse cardiovascular safety to start with than their modern equivalents, estradiol valerate (Progynova) and progesterone (Prometrium).

The study cohort did report an increased risk of breast cancer. However, the increase in risk was incredibly fucking subtle (8 more invasive breast cancers per 10,000 person years) and it's not clear that it would even nullify trans women's class-wide lower risk.

Finally on the WHI study, the actual recommendation of the WHI investigators was that estrogen—progestin therapy doesn't prevent chronic disease, not that it can never be used for anything. Mental health and QoL interventions could very well justify it.

2. In fact, on that note, clinicians do hand out other "ineffective" and "dangerous" medications relatively freely. SSRIs, for example, have a clearly worse risk ratio for stroke than progestogens, adding about 20% more risk, and are not clearly more effective than placebo.

3. There is a 2012 study indicating that spiro may impair breast development. Nobody's done shit about it. The fact that doctors rushed to stretch the WHI study to cover young trans women, but have ignored the Seal study, sends a message about their priorities.

4. Some of the excuses doctors have come up with not to prescribe progesterone are obvious bullshit. It's still quite trendy to say that "it doesn't improve breast development, that's just water retention" when it's beyond doubt that progesterone does not affect water retention.

5. The fact that no researchers have properly investigated whether progesterone improves breast development in 30 fucking years, despite the ongoing shitfight over it, seems very much like they're deliberately avoiding it because they don't want to admit trans women were right.

6. Progesterone has effects other than breast development, but cis doctors absolutely love to steer the conversation onto breast development and nothing else, and scoldingly deny it on those grounds. Trans women are implicitly sexualised, treated as cumbrained and thoughtless.

7. Progesterone has symbolic value. Cis women have more of it than cis men do, and no, it is not just a "hormone of pregnancy". To many trans women forced to walk around with an E-only metabolism, it feels like they're being deliberately obstructed from full womanhood.

In short, the progesterone wars are a macrocosm of trans healthcare in general:
- trans people want an innovation; doctors have a keen eye and a photographic memory for any excuse to stop them getting it
(cont.)

- there are issues with the current system, but when presented with evidence of those issues, doctors suddenly can't read
- doctors are applying laughably uneven and biased evidentiary standards to things trans people want, which is a subject of major trauma for trans people:

a) Blanchard(? — don't remember) deciding to nudge his numbers in the right direction by simply deciding that if a trans woman didn't give him the answer he wanted, she was obviously lying, which made him even more right

b) another therapist, or possibly Blanchard again, doing a desistance study and coding every subject who was lost to follow-up as having desisted, which is outright scientific fraud and would have been rightly howled down as such in any other field

- doctors are presenting the evidence in a clearly fraudulent way, reminiscent of the old "Oh, I'm sorry, I can't prescribe you this female estrogen, Jane, I mean Mr Smith, it'll increase your risk of breast cancer!" [not mentioned: "because you'll have breasts!"]

- doctors are interested in maintaining a metaphysical barrier between trans women and "real" women, because if they can do that they can erode the perception that trans people are full, "real" people, and force them to remain pliant, submissive, controllable

tl;dr — The progesterone debate is fundamentally about doctors asserting that they own their trans patients, the same way conservative parents assert that they own their kids; trans people rejecting the legitimacy of that assertion; and the ensuing screaming match.

Important update: a meta-analysis of which I was not previously aware https://twitter.com/trappychan_/status/1510196692238409730

https://twitter.com/trappychan_/status/1510197755892936710

Pursuant to reader feedback, I should like to clarify that the thirteenth Tweet in this thread is not intended to invalidate my sisters who *are* cumbrained and thoughtless. I just think it's poor clinical practice to presume it of transfems as a class

Update on part of this thread: I've received new information about Seal et al. (2012), which I mentioned in a positive context upthread. While my remarks upthread remain technically true, I wrote them from thinking the study was more robust than it was. In particular, it:

1. does not make a robust argument for a causal link between spiro administration and presentation for breast augmentation (BA);
2. uses BA as an implicit proxy for breast development, but includes no actual data on breast development;

3. has a very inadequate sample size, much smaller than is initially apparent — an ideal sample size would be 400+, enrollment in the whole study was 330, the size of the spiro group was 22;
4. lack of standard controls against p-hacking (i.e., showing patterns where none exist).

In saying that the study might show that spiro impairs breast development, I made a claim that even the study itself did not, and committed cum hoc ergo propter hoc* ("with this because of this," i.e., claiming "correlation equals causation").

* haha yes

I'm grateful to the mutual who advised me of this, and to Aly W. of @TransfemScience, who wrote the initial analysis as part of her fact check of the Powers Method: https://transfemscience.org/articles/powers-fact-check/

I feel like this affects primarily my claim about what doctors prioritise; I don't see that it affects the rest of the thread, but if anyone can see that it does, then that's obviously something I both need to, and would love to, know about.