[Explainer] half-life is 168 hours. that is why your injection day barely matters.
Every week somebody asks whether Tuesday is better than Sunday, and every week the answer is buried under anecdote. Semaglutide's terminal half-life is roughly 168 hours — about a week. Practical consequences: Steady state takes 4–5 weeks per dose step. What you feel in week one of a new dose is not what that dose…
The one refinement I would add: the subjective experience is not flat even when the plasma level nearly is, because gastric emptying effects are more pronounced in the first few days after a dose than at the end of the interval.
So people reporting a "good week and a flat week" are not imagining it — they are describing a motility effect on top of a fairly stable concentration. Two different curves, one week.
this is the correction the post needed and i will fold it into the wiki version. concentration flat, effect not flat.
this explains why moving to friday evenings worked for me. it did not change the drug, it moved the worst two days onto a weekend.
sunday 8pm, 61 weeks straight, same logic in reverse. consistency is the whole trick and the day is arbitrary.
so the correct answer to "which day" is "the one you will not forget"?
exactly that. it is the only variable in the question that has an effect size.