Missed GLP-1 Dose Calculator: Ozempic, Wegovy, Mounjaro, Zepbound

1. Choose Mounjaro or Zepbound, Ozempic, or Wegovy injection. The checker reads the US labels; tap "In the UK?" to use the UK rules instead.
2. Enter the date and time of your last shot, or say you don’t know the time, and check your usual shot day. The checker reads the time now from your device.
3. Read the verdict and its deadline to the hour, and your next dose on your usual day. To move your shot day for good, pick the new day and the checker says whether it works yet.
4. If two or more doses have passed, the checker shows the dates, how much of your last dose is left in the half-life model, and what your label says, in a note you can print. Add the next dose to your calendar.

The checker assumes your next dose is due 7 days after the one you missed. If you have moved your injection day recently, your Wegovy window may be shorter than it shows.

Each weekly injection has its own missed-dose rule and its own minimum gap between two doses, set in section 2 of the US labels for Zepbound, Mounjaro, Ozempic and Wegovy.

The checker reads each window to the hour. These are its answers at the edges, on a regular 7-day week.

At exactly 5 days late, your next Wegovy dose is exactly 48 hours away. The label wording covers neither "more than" nor "less than" 2 days, so the checker says skip.

Pensday keeps the date of every shot, which gives you the hours since your last dose before you decide.

On a regular week the US Wegovy rule closes at 7 − 2 = 5 days late, the same point as the Ozempic rule, and that is what the checker uses. If your next dose is due sooner, for example 5 days after the missed one because you are moving your injection day, count back 2 days from that date yourself, which closes the window at 5 − 2 = 3 days late. The UK Wegovy SmPC counts forward from the missed dose and allows 5 days (Wegovy SmPC, section 4.2); missed-dose rules by brand sets the US and UK wording side by side.

A late shot lets the level fall further before it goes in. Tirzepatide’s half-life is about 5 days (Mounjaro prescribing information, section 12.3), so a dose taken 2 days late follows 9 days of decay instead of 7. Just before that late shot, about 29% of the level after your last dose is left (0.5 to the power 9 ÷ 5), against 38% on schedule. The GLP‑1 plotter draws the on-schedule weekly curve those percentages come from.

For two or more missed doses the checker shows what each label says and dates your last dose. After 2 or more missed doses in a row, the US Wegovy label says to restart the dose escalation at a lower dose (Wegovy prescribing information, section 2.4). The Ozempic, Mounjaro and Zepbound labels have no rule for several missed doses. Once you restart, the dose titration planner dates the steps back up.