What to Do If You Miss a GLP-1 Injection
Missing a weekly GLP-1 injection happens. You travel, you get sick, you lose track of the day. The good news is that missing a single dose isn't a crisis — but what you do next depends on how many days have passed, and the rules differ slightly between semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro, Zepbound).
Here's exactly what to do.
The Rules for Wegovy and Ozempic (Semaglutide)
Semaglutide has a relatively long half-life — it stays active in your system for a while after injection. This means missing a single dose doesn't immediately undo your progress, and there's a window in which you can still take the missed dose without major disruption.
If less than 5 days have passed since your scheduled injection day:
Take the missed dose as soon as you remember. Then resume your regular weekly injection schedule from your original day. Don't shift your future injection days to accommodate the late dose.
If 5 or more days have passed since your scheduled injection day:
Skip the missed dose entirely. Don't inject it. Simply wait until your next regularly scheduled injection day and continue as normal.
The Rules for Mounjaro and Zepbound (Tirzepatide)
Tirzepatide follows a similar but slightly tighter rule. The window is four days rather than five.
If less than 4 days have passed since your scheduled injection day:
Take the missed dose as soon as you remember. Then resume your regular weekly injection schedule.
If 4 or more days have passed since your scheduled injection day:
Skip the missed dose. Resume your regular schedule on your next scheduled injection day.
What You Should Never Do
Never take two doses in the same week to make up for a missed one. Doubling up significantly increases your risk of severe side effects — particularly nausea, vomiting and other gastrointestinal problems. One missed dose is not worth risking a week of feeling unwell.
Will One Missed Dose Affect My Progress?
Probably very little. GLP-1 medications have a long duration of action — semaglutide has a half-life of approximately one week, meaning it takes about a week for half the dose to clear your system. Missing one injection means your levels will dip lower than usual, but the medication doesn't vanish from your system overnight.
You may notice your appetite returns somewhat in the days after a missed dose, or that food feels less satisfying. This is normal and temporary. Once you resume your regular injections, things should return to your usual baseline within a week or so.
What About Side Effects After Restarting?
If you've missed multiple doses in a row — say, you ran out of medication and there was a delay in getting more — some people experience side effects returning when they restart, similar to when they first began the medication. This is more likely if you've been off the medication for several weeks. In those cases, your prescriber may recommend restarting at a lower dose and escalating again rather than jumping back to your previous maintenance dose.
Always check with your prescriber if you've had a gap of more than a few weeks.
How to Avoid Missing Injections
The simplest approach is to tie your injection day to something you already do every week. Picking Sunday morning, or a specific day when you have a routine, and linking it to a habit you already have — morning coffee, for example — makes it much harder to forget. Keeping your medication in a visible place in your fridge (rather than tucked at the back) also helps.
Many people find it useful to log each injection immediately after taking it, which also creates a record if you're ever unsure whether you've injected that week.
Never lose track of your last injection again
The GLP-1 HQ tracker logs each injection with date, medication and dose — and automatically shows your next injection date (+7 days). Your full history is always one tap away.
Open the free tracker →Changing Your Injection Day
If you want to shift your regular injection day permanently — say, from Monday to Thursday — you can do so, as long as you maintain a minimum gap between doses. For semaglutide, the minimum gap is three days. For tirzepatide, the minimum gap is also three days. So if your last injection was Monday and you want to move to Thursday, wait at least until Thursday of that same week and then continue on Thursdays going forward.
If in doubt about any of the above, your pharmacist is usually the fastest and most accessible resource — they know your medication and can give you guidance specific to the product you're using.
Medical disclaimer: This article reflects the general prescribing guidelines for semaglutide and tirzepatide at the time of writing. Always follow the specific instructions provided by your prescriber or pharmacist, as individual circumstances may vary. Do not adjust your dose or schedule without professional guidance.