Evidence-graded answer
What happens if I miss a weekly GLP-1 dose?
If within 5 days: take the missed dose as soon as you remember, then resume the regular schedule. More than 5 days late: skip it and inject your next scheduled dose. Never double up.
Semaglutide and tirzepatide both have ~7-day half-lives, which is why missing a dose by 1-2 days has minor effect — drug levels stay near-therapeutic.
If you miss 2 consecutive weekly doses, contact your prescriber. Some clinicians prefer re-titrating from a lower dose to avoid GI side effects on resumption.
If you've been off therapy for 3+ weeks, almost all clinicians require re-titration from the starting dose.
Source: Wegovy prescribing information, accessdata.fda.gov