Key takeaways
- Tirzepatide: if a dose is missed, take it within 4 days (96 hours) of the scheduled day; if more than 4 days have passed, skip it and take the next dose on the regular day. Semaglutide (Wegovy): within 5 days; otherwise skip.
- Never take two doses within three days of each other for tirzepatide, or double up to catch up for either drug.
- After two or more consecutive missed weekly doses, or any break of about two weeks or more, most prescribers restart at a lower dose and re-escalate, because gastrointestinal tolerance is lost within a few weeks.
- Wegovy's label says that after more than two missed doses, re-initiation at a lower dose may be considered to reduce gastrointestinal symptoms; tirzepatide's label does not specify a restart dose, and clinicians commonly step back one or two levels.
- Missed doses cost weight-loss momentum and can trigger a return of appetite within a week; reorder ten days early and keep one dose in reserve.
Why timing matters less than it feels, until it matters a lot
Tirzepatide and semaglutide have half-lives of about five and seven days, which is what makes weekly dosing work and what makes a single late dose a small event: levels fall slowly, and a dose a day or two late is absorbed into a curve that was still well above zero. The labels reflect that with generous catch-up windows. A missed dose becomes a large event only when the gap is long enough for tolerance to fade, because the gastrointestinal side effects that the titration schedule exists to manage return at full strength when the drug is restarted at full dose after a break.
The label rules
Tirzepatide (Zepbound, Mounjaro, and compounded tirzepatide prescribed on the same schedule). If a dose is missed, take it as soon as possible within 4 days (96 hours) after the missed dose. If more than 4 days have passed, skip the missed dose and take the next dose on the regularly scheduled day. Do not take two doses within 3 days of each other. The day of the week can be changed if the time between two doses is at least 3 days.
Semaglutide 2.4 mg (Wegovy). If a dose is missed and the next scheduled dose is more than 2 days away, take it as soon as possible; if the next dose is less than 2 days away, skip the missed dose and resume on the regular day. If more than two consecutive doses are missed, resume as prescribed or, in the prescriber's judgment, re-initiate at a lower dose to reduce gastrointestinal symptoms. The dosing day can be changed as long as at least 2 days separate doses. Ozempic's rule is the same 5-day window with a 48-hour minimum interval.
Compounded products carry the pharmacy's label and the prescriber's instructions; in practice prescribers apply the brand rules, and a patient whose instructions say otherwise should ask why.
One missed dose
Take it within the window and resume. Expect a small return of appetite in the days before the late dose and possibly a little more nausea after it, because the peak is slightly higher relative to the trough. Do not compensate by taking the next dose early; keep the minimum interval.
Two missed doses
Two consecutive missed weekly doses means roughly three weeks between injections, and by then drug levels are a small fraction of steady state and gastrointestinal tolerance has largely reset. Wegovy's label explicitly allows re-initiation at a lower dose in this situation; tirzepatide's label is silent on a restart dose, and the common clinical practice is to step back one or two dose levels (for example from 10 mg to 5 or 7.5 mg) and re-escalate every four weeks. Contact the prescriber before injecting; a telehealth provider that will not answer that question within a day is telling you something about its follow-up.
Restarting after a longer break
After a month or more off, whether from a shipping gap, a provider switch, a pregnancy, surgery or a decision to stop, the restart is a re-initiation. Most patients will have regained some weight (SURMOUNT-4 and STEP 4 measured about two-thirds of the loss returning within a year of stopping) and all will have lost gastrointestinal tolerance. Restarting at the previous maintenance dose commonly produces the nausea and vomiting of the first weeks at a higher intensity than the first time, and occasionally dehydration serious enough to need care; this is one of the situations in which compounded-vial dosing errors have caused harm, because a patient restarts at "the dose I was on" with a vial of a different concentration. The safer sequence: confirm the vial concentration, restart at the lowest dose that was previously tolerated without difficulty (often 2.5 to 5 mg of tirzepatide or 0.5 to 1 mg of semaglutide), and re-escalate every four weeks. Some prescribers restart at the starting dose regardless; that is conservative and reasonable after a break of several months.
Moving injection day
Both labels allow a change of day with a minimum interval (72 hours for tirzepatide, 48 hours for semaglutide). Move once and keep the new day. Injecting in the evening puts the peak of side effects into sleep; injecting the day before a rest day gives a buffer. Do not shorten the interval below the minimum to reach a preferred day faster.
What a missed dose costs
A week's gap costs a week of drug exposure and usually a temporary return of appetite; it does not erase progress. Two or three weeks costs the tolerance built over months and often a step back in dose, which means a slower climb back to the maintenance dose and a pause in weight loss. The avoidable version is the supply gap: order refills at least ten days before running out, keep one dose in reserve in hurricane season and winter, and, when switching providers, order from the new one before the old supply ends. The shipping and refills page covers timing, and the switching guide covers transfers.
When to call rather than inject
Vomiting that prevents fluid intake, severe abdominal pain, symptoms of low blood sugar in a patient on insulin or a sulfonylurea, or any uncertainty about the vial concentration are reasons to contact the prescriber before the next dose. A restart is also the moment to re-read the dosing sheet against the vial label; the dosing checklist sets out the arithmetic.
Frequently asked questions
What should I do if I missed my tirzepatide dose?
Take it as soon as you remember if it is within 4 days (96 hours) of the scheduled day, then resume the usual day. If more than 4 days have passed, skip the missed dose and take the next one on schedule. Do not take two doses within 3 days of each other.
What if I missed my Wegovy dose?
Take it within 5 days of the missed day, then resume the usual schedule; if more than 5 days have passed, skip it. If you miss more than two consecutive doses, contact your prescriber, because the label allows re-initiation at a lower dose to limit gastrointestinal symptoms.
How do I restart tirzepatide after two weeks off?
Contact the prescriber before injecting. After a break of about two weeks or more, tolerance to gastrointestinal effects fades, and most clinicians restart one or two dose levels below the previous dose, then re-escalate every four weeks if tolerated. The label itself does not prescribe a restart dose.
Can I change my injection day?
Yes. Tirzepatide can be moved to a new day as long as at least 3 days (72 hours) separate doses; Wegovy as long as at least 2 days (48 hours) separate them. Adjust once and keep the new day.
Sources
- Zepbound (tirzepatide) prescribing information, Eli Lilly, 2025 (missed dose; dosing).
- Mounjaro (tirzepatide) prescribing information, Eli Lilly, 2025.
- Wegovy (semaglutide) prescribing information, Novo Nordisk, 2025 (missed dose; re-initiation).
- Ozempic (semaglutide) prescribing information, Novo Nordisk, 2025.
- Aronne LJ et al. SURMOUNT-4. JAMA 2024;331:38-48 (effects of discontinuation).
- Rubino D et al. STEP 4. JAMA 2021;325:1414-1425.
Citations are to primary sources (peer-reviewed trials, FDA labeling and announcements, and provider pricing pages). See our sources policy and corrections log.