This is the version of the explanation I wish somebody had given me, written down before I forget what confused me. It is about the titration schedule, and it is deliberately narrow — everything I am not confident about is marked as such.
What is actually established
Holding longer is the underrated move. A step that is uncomfortable at week two is frequently comfortable at week six with no change in dose, because the gastric-emptying component tachyphylaxes while the appetite effect persists. Escalating at week two throws that adaptation away.
The condition it depends on
That is right for the weekly injectables. For the daily agents the interval logic is different and the four-week convention does not transfer.
The practical version
The arithmetic in one line: half-life about a week, so steady state at four to five weeks, so a four-week interval is one steady state per step. Two-week intervals mean every step is dosed onto a rising curve.
What I am not sure about
The bit I cannot resolve on my own is what the trials actually did with participants who could not tolerate a step, because that is the situation I am in and the protocol summaries skip it. Numbers rather than impressions, if you have them.
— JennaRN · corrections welcome and will be edited into this post with credit