What If I Miss a Dose of Tirzepatide or Semaglutide? What to Do

The Zepbound prescribing information, revised August 2026, states in section 2.3: "If a dose is missed, instruct patients to administer ZEPBOUND 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 administer the next dose on the regularly scheduled day. In each case, patients can then resume their regular once weekly dosing schedule."

The Mounjaro label, the type 2 diabetes product containing the same molecule, carries the identical instruction.

For tirzepatide the rule is a count, not a judgement: four days from the dose you missed. Day five is not a grey area in the label's own terms — past 96 hours, the instruction is to skip.

The Wegovy prescribing information, revised June 2026, works from the other end of the week. If one dose of Wegovy injection is missed and the next scheduled dose is more than 2 days away, administer it as soon as possible; if the next scheduled dose is less than 2 days away, do not administer the missed dose, and resume dosing on the regularly scheduled day of the week.

Instead of counting forward from the dose you missed, that counts backward from the dose you are about to take, protecting a minimum gap of roughly 48 hours between injections. On a Monday schedule, a dose remembered by Saturday is generally taken and one remembered on Sunday generally is not. What the label guards is the interval, not the calendar.

The same label adds the part that governs longer gaps: if 2 or more consecutive doses of Wegovy injection are missed, reinitiate dosage escalation at a lower dosage to reduce the risk of gastrointestinal adverse reactions.

The Ozempic injection label sets a different number again: "If a dose is missed, administer OZEMPIC as soon as possible within 5 days after the missed dose. If more than 5 days have passed, skip the missed dose and administer the next dose on the regularly scheduled day."

This is the source of the widely quoted "five-day rule" for semaglutide. It is real and current, and it belongs specifically to the diabetes product — quoting it back at a weight-management prescription is the commonest way people get this wrong.

None of these are your directions. They are the reference points a physician reasons from.

Both tirzepatide labels state that the day of weekly administration can be changed, if necessary, as long as the time between the two doses is at least 3 days (72 hours). The Ozempic injection label sets that minimum at 2 days. Same principle in different clothes: the labels protect a minimum interval, and everything else is flexible. The Wegovy label makes that explicit — administer once weekly, on the same day each week, at any time of day, with or without meals, and the time of day and injection site can be changed without dose adjustment.

The Mounjaro label gives tirzepatide an elimination half-life of approximately 5 days, which it describes as enabling once-weekly dosing. The Zepbound label puts it at approximately 5 to 6 days in patients with overweight or obesity, with the median time to maximum plasma concentration after injection at 24 hours. A population pharmacokinetic analysis of tirzepatide in CPT: Pharmacometrics & Systems Pharmacology in 2024 describes the same picture across the phase 3 programme.

Four days is under one half-life, which is why the window is not arbitrary: injecting at day 11 instead of day 7 tops up a level that is lower than usual, not absent.

The Wegovy label states that with an elimination half-life of approximately 1 week, semaglutide will be present in the circulation for about 5 to 7 weeks after the last dose of 2.4 mg. The Ozempic label makes the same point for its own product: about 5 weeks after the last dose. A 2024 systematic review of semaglutide pharmacokinetics in Drug Design, Development and Therapy gathers the published human data behind those figures.

Semaglutide is the slower of the two, which is why its weight-management instruction is written as a minimum interval rather than a maximum delay: with a one-week half-life, the risk being managed is not the gap, it is two injections landing too close together.

Because both molecules persist for days, one missed injection produces a trough in exposure rather than a stop. Some people notice appetite returning late in the second week; others notice nothing, and neither reaction means anything is wrong. What it does mean is that you cannot make yourself current by injecting twice, because the level you are restoring is still partly there.

Weekly medication with a multi-day half-life accumulates for several weeks before what goes in each week equals what clears. The Zepbound label reports that steady-state plasma tirzepatide concentrations were achieved following 4 weeks of once weekly administration, and its escalation schedule matches: 2.5 mg once weekly for 4 weeks, then increases in 2.5 mg increments after at least 4 weeks on the current dose. The Wegovy label titrates every 4 weeks toward its maintenance dosage. Your own schedule is set by your physician and printed on your medication.

The labels also treat "getting used to it" as a documented pattern. The Zepbound label states that the majority of nausea, vomiting and diarrhea events occurred during dose escalation and decreased over time. Tolerance is not a property of the dose number; it is a property of your recent history with it.

The Wegovy label reports that steady state exposure increased proportionally with dose across its studied range. Stacking two injections within a couple of days is, in exposure terms, a temporary jump to a strength you were never titrated to — which is why the labels protect a minimum interval rather than simply telling you not to miss doses.

This is what turns an unpleasant few days into a medical problem. The Zepbound label describes postmarketing reports of acute kidney injury, in some cases requiring hemodialysis, and notes that the majority of reported events occurred in patients who experienced gastrointestinal adverse reactions leading to dehydration such as nausea, vomiting or diarrhea. The Wegovy label carries a comparable warning about acute kidney injury and worsening of chronic renal failure. The chain is short: stacked dose, prolonged vomiting, fluid loss, kidney strain.

Drawing half a dose to split the difference is the same error in a smaller package: your vial is dispensed at a specific concentration with a specific volume printed on it, and improvised volumes are how people lose track of what they actually took.

Contact your prescriber and tell them what you injected and when, then focus on fluids and small, plain meals. If you cannot keep fluids down, if vomiting continues beyond a day, if you are passing much less urine than usual, or if you develop severe abdominal pain radiating to your back, that is a same-day medical call rather than a message.

Most restart guidance in circulation is clinical convention. One approved label states it outright: the Wegovy prescribing information instructs that if 2 or more consecutive doses are missed, reinitiate dosage escalation at a lower dosage to reduce the risk of gastrointestinal adverse reactions. That is the only place in these four labels where a specific gap is tied to a specific restart instruction; the tirzepatide labels carry no equivalent sentence, which is why that decision sits squarely with the prescriber.

Restarting lower costs a few weeks of titration. Restarting at your old strength after a month away and spending a week unable to keep food down costs the same few weeks, plus the week you were unwell, plus the real possibility that you stop treatment altogether. The downside is asymmetric, and prescribers price it accordingly.

Two randomized withdrawal trials are the closest published evidence to "what happens when the medication stops".

STEP 4, published in JAMA in 2021, enrolled adults with overweight or obesity and without diabetes. The 803 participants who reached the 2.4 mg maintenance dose during a 20-week run-in were randomized to 48 weeks of continued semaglutide or a switch to placebo. Mean body weight change from week 20 to week 68 was −7.9% with continued semaglutide and +6.9% after the switch to placebo.

SURMOUNT-4, published in JAMA in 2024, used the same design for tirzepatide. Adults with obesity, or overweight with a weight-related complication, excluding diabetes, took the maximum tolerated dose (10 or 15 mg once weekly) for a 36-week open-label lead-in, during which mean weight reduction was 20.9%. The 670 completers were randomized to continue tirzepatide or switch to placebo for 52 weeks; mean percent weight change from week 36 to week 88 was −5.5% with tirzepatide and +14.0% with placebo.

They measured months of complete withdrawal, not a forgotten injection. Nothing in either tells you what one skipped week does. What they establish is the direction of travel over a long absence, which is why a pattern of missed doses is a different conversation from a single one. The efficacy findings in both programmes — SURMOUNT-1 in the New England Journal of Medicine in 2022 for tirzepatide, STEP 1 in the same journal in 2021 for semaglutide — were generated on uninterrupted weekly schedules at maintained strengths.