Why should Estrogen not be applied to the breasts?

Estradiol valerate 5–20mg i.m./2 weeks or cypionate 2–10mg i.m./week

injecting estradiol valerate once every 2 weeks is pretty wild, tbh - it has a relatively short half-life when injected and has a spikey metabolism

it also suggests injecting cypionate more frequently (once a week) despite a longer half-life‼️

I find this very suspicious and unlikely to result in the best outcomes.

EDIT: the guidelines are very old, from 2013

EDIT2: unsurprisingly, these guidelines were found to be problematic and were revised in 2024 to update estradiol valerate doses to lower and more frequent doses of ~5 mg / week, this is much more reasonable and aligns with what I found reasonable (I myself inject 4 mg once a week.)

one of the co-authors of the revised guideline was Joshua Safer, who was one of the co-authors of the original 2013 guidelines fwiw

It might be good to find more up to date guidelines, I wouldn’t take these 2013 guidelines too seriously.

EDIT3:

My point is: go to scientific sources for fact checking before believing anything written here.

@leftascenter@jlai.lu the problem is that there are rarely sufficient biomedical sources, research, or empirical evidence on specific doses or how to use this medicine for trans patients - the medications we take are all off-label use, and the evidence about risks are all extrapolated from studies of cis people (and sometimes, studies on older synthetic medications that aren’t even used anymore - so the guidelines and risk estimates are often based on poor evidence / reasoning - resulting in many doctors falsely equating injecting bioidentical estrogen to the risks of taking synthetic horse estrogens orally).

And for cis women this lack of body of evidence is a familiar frustration, since women are less studied and have long been excluded from clinical studies, they likewise struggle to have good empirical evidence to turn to about what doses of medications are safe for them, etc.

As a result, the trans community has had to develop best practices and cooperate and share information to fill in the gaps where medicine has left uncertainty.

As an example, my endocrinologist first put me on a dose of 5 mg of estradiol valerate once every two weeks. If I had just trusted him and followed what he said, I might not be alive today - I had to advocate and fix the dose, and it took me a lot of experimentation and work to figure out a dose and frequency that worked. The doctors really don’t know anything, so we have to educate ourselves. Part of what was helpful was being able to find online communities of other women in my position sharing what doses and frequencies they found helpful. Obviously, you still have to get blood estrogen levels tested to verify the dose is sufficient, etc. - but the idea of prescribing 5 mg once every two weeks shows a profound ignorance (or complete indifference) to how that medication is actually metabolized. For comparison it would be like telling someone to take an ibuprofen three times a week to treat the flu. They’re going to need it more frequently, a single ibuprofen pill has a half life of 2 - 4 hours, and after 8 hours it’s probably mostly out of your system.

I am sure you are well intended, but it comes across as a cis ally coming into the trans community and telling us what to do without sufficient knowledge or experience to make your advice helpful to us.

You would be right that we should fact check and ground our practices in biomedicine, but until biomedicine has actually accumulated that body of evidence, we’re having to stumble around in the dark as best we can.

The topic at hand best illustrates this: you will not find any body of evidence about the appropriate use of progesterone in transfeminine individuals because it does not exist. It’s complete guesswork, nobody knows what the right dose or frequency is.

However, I still like to base my guesswork on the limited pieces of evidence we have - particularly by looking at the blood levels of progesterone in cis women during their menstrual cycle and comparing those levels to the levels we see when we administer oral progesterone rectally, we can reason that rectal administration could theoretically provide sufficient progesterone levels to mimic cis female levels of progesterone. But I don’t even have the option of getting blood drawn to test my progesterone levels, so it is even more in the dark than taking estrogen. Progesterone is a 24 hour cycle, making that blood draw quite impractical (esp. you take the progesterone at night).

All this to say, your advice is irrelevant in this context, even if it’s well-intended.

Unfortunately this says nothing about progesterone.

Ironically doesn’t mention progesterone.

…what?