Accepted answer
four weeks at 2.4 mg is 28 days at one dose level — and the arithmetic the question hides is that it also moves every dose above 2.4 mg back by 28 days. Whether that reduces headache depends on which quantity it tracks. A symptom driven by the dose itself is unchanged by waiting: 2.4 mg is 2.4 mg on day 1 and on day 28. A symptom driven by the rate of change has 28 days of no change to settle in, which is the case the hold is actually made for. The distinction is testable on your own record: plot headache against days-since-last-increase rather than against dose, and if the peaks line up with the increases the hold is doing something. Escalation schedules are set by a prescriber, and nothing here is medical advice.
Start with the half-life, because the interval between steps should be at least four half-lives or you are escalating before the previous step has expressed itself.
The published semaglutide weight-management schedule steps 0.25, 0.5, 1.0, 1.7 and 2.4 mg at four-week intervals, with 0.25 mg as an initiation step rather than a therapeutic one.
Mechanically, holding a step for eight weeks instead of four is a legitimate approach with no efficacy cost at the destination, and it is what the trials effectively did for anyone who tolerated poorly.
Four to five half-lives to steady state is standard first-order pharmacokinetics and gives the four-week interval directly from the one-week half-life.
Nothing here is medical advice, and research-use compounds are not approved for human use.
Hold rather than escalate while symptoms are active. Always.