Tirzepatide Hub

Calculator

Missed dose and day-change helper

Enter when the dose was scheduled and when you can take it. The helper applies the rule from the Zepbound and Mounjaro labels: take a missed dose within 4 days (96 hours), otherwise skip it and keep the regular day. A second mode checks a planned change of injection day against the label's 72-hour minimum spacing.

By FormBlends editorial teamAssumptions checked September 4, 2026 Runs in your browser; nothing is sent to a server

What it computes

The 96-hour missed-dose window and the 72-hour day-change rule, applied to your times.

Never pre-fills a dose

Inputs

Your usual injection day and roughly the usual time.

Pre-filled with the current time on this device. Change it to test a later moment.

What the label says

Enter the scheduled time. The Zepbound and Mounjaro labels use one rule: take the missed dose if it is within 4 days (96 hours); if more than 4 days have passed, skip it and take the next dose on the regular day.

Formula
hours late     = now - scheduled time
take now       = 0 <= hours late <= 96
skip           = hours late > 96
next regular   = scheduled time + 7 days (unchanged)
day change ok  = (new dose time - last dose time) >= 72 hours

Example: scheduled Monday 9:00, remembered Thursday 20:00. That is 83 hours late, inside 96, so the label says take it and keep next Monday. Remembered Friday 10:00 is 97 hours, so skip and take Monday's dose as normal.

Assumptions, checked September 4, 2026
  • Zepbound section 2.3 and Mounjaro section 2.1: administer a missed dose as soon as possible within 4 days (96 hours); if more than 4 days have passed, skip it and take the next dose on the regularly scheduled day, then resume the weekly schedule.
  • Same sections: the day of weekly administration can be changed if the time between the two doses is at least 3 days (72 hours).
  • Times are compared on this device's clock and time zone. Cross a time zone and the hour count can be off by the zone difference; the day count will still be right.
  • The tool never suggests doubling a dose, changing a dose, or catching up on more than one missed dose.
  • Compounded tirzepatide carries no FDA label. These are the brand rules; your prescriber's written instructions govern.

This calculator is an arithmetic aid for medication a licensed prescriber has already prescribed. It does not recommend a dose. Confirm any result with your prescriber or pharmacist before use.

Sources

  1. Zepbound (tirzepatide) prescribing information, Eli Lilly, DailyMed set id 487cd7e7-434c-4925-99fa-aa80b1cc776b, revised 08/2026
  2. Mounjaro (tirzepatide) prescribing information, Eli Lilly, DailyMed set id d2d7da5d-ad07-4228-955f-cf7e355c8cc0, revised 08/2026

Read before you use it

Guides for this calculator

Paper-cut illustration of a syringe with plain tick marks beside a slide rule and a ruler

Missed a tirzepatide dose? The 96-hour rule and the 72-hour rule

You'll get: The label says a dose up to four days late can still be taken, and your usual day does not move.

Exactly what the Zepbound and Mounjaro labels say about a late dose, a skipped dose, and changing your injection day, with worked examples and a helper that applies the rules to your times.

Updated September 4, 2026

Educational, not medical advice. Read the medical disclaimer.