Accepted answer
Week 4 is day 28: on a four-week ladder that is week 4 of dose step 1, and — at the seven-day half-life this class runs on — 4 half-lives in. Steady state is about five half-lives, so day 35 is where the concentration stops climbing on its own. Day 28 is 1 weeks short of it, so the level is still rising even though the dose has not changed. That distinction is most of the question: at week 4 of a step, an effect that is still accumulating is indistinguishable from one that is not resolving unless you know which side of day 35 you are on. Nausea in this class tracks the rate of change more than the level: the trial programmes report it clustered in the fortnight after each step and decaying across the weeks that follow, which is why the week number is worth locating on the ladder before anything else. Dose decisions are made under supervision, and nothing here is medical advice.
More usefully, this is the most common adverse effect in the class and the one with the most consistent management advice.
Nausea persisting for more than a few weeks at a stable dose, or accompanied by severe abdominal pain, is outside the ordinary pattern and needs assessment rather than management.
Practical measures with the most support: smaller meals, stopping at the first sense of fullness, reducing fat and fried foods, avoiding lying flat after eating, and keeping fluid intake up between meals rather than with them.
Tachyphylaxis of the gastric-emptying effect with continued exposure is documented for the long-acting agents and is the mechanistic basis for tolerance.
Nothing here is medical advice; I am describing a pattern, not managing anybody.
Smaller meals, less fat, stop at first fullness, fluids between meals.