I really don’t know why some of the more conservative dosing recommendations still give two week dosing schedules for EV. It has a lower half life than cypionate and should be injected more often, assuming you’re aiming for stable levels (most people are). A lot of our original recommendations for transfem people were based around studies for populations with prostate cancer and menopause, and it seems like dosing strategies for them have stuck around.
I personally wouldnt ever go over a week long dosing of ev, and would likely switch to twice weekly injections if were I on it. The people over at transfemscience.org put together a neat way to visualize the difference in esters for achieving a steady state dose based on the pharmacokinetics of them all. Basically, at this point if I get a recommendation from a doctor for 14 day dosing of EV, I’m going to assume they’re not up to date on current feminizing hrt research and are likely going to also be giving old information about things like IM vs SubQ injections.
Finally, nobody should ever be paywalled from medical information (and it’s pretty abhorrent that this research even has to have hoops to jump around to get through). Just as an fyi for anybody else reading this, most articles that aren’t brand newwill have a copy of it you can access by its doi number on sci-hub.ru (or another mirrored domain, searching scihub normally gives a list of current working addresses). In the case where it isn’t available yet, the journal should provide a way to email them asking for specific articles for patient access.
Go fiddle with the calculator on the website I linked to see how injecgion time changes peak-trough gap in the hormone curves. But generally I want stable levels because research shows we need a minimum amount of estrogen in order to have feminizing effects. We don’t want to overshoot it because your body will create SHBG at too high of levels. I’ve never seen any research that hints at varying levels be more effective.