Collecting this in one place because it comes up every few weeks and the answer is always assembled from scratch. It is about nausea, and it is deliberately narrow — everything I am not confident about is marked as such.
What is actually established
The line between titrate-through and stop is not severity, it is trajectory and what else is present. Nausea that peaks and improves within a week is the expected pattern. Nausea that is escalating, or that comes with severe upper-abdominal pain radiating to the back, or that prevents fluids for more than a day, is a different conversation and belongs with a clinician the same day.
The condition it depends on
A caveat: adaptation applies to gastric emptying and not to everything. If your problem is the aversion rather than the fullness, waiting does less, because the aversion is central and it is the mechanism working as intended.
The practical version
Trial-level incidence runs roughly 20 to 25% for nausea at the higher dose tiers and 12 to 17% for diarrhoea, with most events mild to moderate and concentrated in the weeks after each escalation.
What I am not sure about
The narrow version of the question is what distinguishes the nausea you can titrate through from the nausea that means stop. Not looking for reassurance. Looking for the part I have got wrong.
— bbq_ray_KC · corrections welcome and will be edited into this post with credit