What to do if you miss a dose of Mounjaro or Wegovy
Peter Paumgardhen | Last update: 23rd December 2025
Missed your weekly injection of Mounjaro or Wegovy? Don’t panic. It happens – and there’s usually a safe and simple way to get back on track.
This guide explains exactly what to do if you forget a dose of your weight loss medication, how timing affects your treatment, and how to avoid missing a dose again in the future.
If you’re new to GLP-1 drugs, also read: How GLP-1 weight loss drugs work and How do I get a weight loss drug prescription?
What to do if you miss a dose
If it’s been LESS than 4 days since your scheduled dose:
- Take the dose as soon as possible.
- Then, go back to your usual injection schedule (same day each week).
- Example: If your usual injection day is Monday and you forgot, you can still inject on Tuesday, Wednesday, Thursday or Friday.
If it’s been MORE than 4 days:
- Skip the missed dose.
- Wait until your next scheduled injection day.
- Do not take a double dose to make up for the one you missed.
This guidance is based on manufacturer advice for both Mounjaro (tirzepatide) and Wegovy (semaglutide). It also aligns with NHS and pharmacy guidelines.
Why timing matters
GLP-1 drugs are long-acting and injected once a week. But they still rely on consistency. Missing a dose or spacing doses too far apart can:
- Reduce effectiveness
- Trigger side effects when you restart
- Slow down your progress
This is especially true when you’re increasing your dose. Most users move up gradually (e.g. from 2.5 mg to 5 mg), and interruptions can make the next jump harder on your body.
If you’re switching providers and risk a delivery delay, plan ahead: How to switch pharmacies
What if I miss two or more doses?
If you’ve gone more than 2 weeks without an injection:
- Contact your doctor, clinic, or prescribing pharmacy.
- They may advise going back to a lower dose to minimise side effects.
Why? Your body needs time to adjust to each level of medication. Missing multiple doses can be like starting again — and jumping straight to a high dose might cause nausea, bloating, or fatigue.
Read: Weight loss drug side effects
What if I took the dose too early?
It’s less common, but sometimes people accidentally inject their next dose a day or two early. If this happens:
- Don’t panic — a slightly early dose is usually OK.
- Wait 7 days from the early dose before your next one.
- Going too early repeatedly can lead to higher drug levels than intended, so try to stick to your weekly schedule moving forward.
Tips to stay on track
Here are some simple ways to help you remember your weekly injection:
- Pick a memorable day (e.g. Sunday night or Monday morning)
- Set a recurring alarm on your phone
- Add it to your calendar or weekly planner
- Store your pen in a visible place in the fridge
- Tick off your dose in a treatment tracker or journal
Read: Managing your weight loss treatment
If you’re not sure what to do…
Always err on the side of caution. If you:
- Don’t know when your last dose was
- Aren’t sure if it was late or early
- Feel unwell after restarting
Speak to your pharmacy, healthcare provider or prescriber. They can advise whether to continue, pause, or restart at a lower dose.
Final word from SlimrChat
A missed dose doesn’t mean failure. Life happens. What matters is how you respond.
Get back on schedule, don’t double dose, and use it as a chance to fine-tune your routine.
“I missed a week while away and panicked — but it was fine. I just picked up again and it reminded me to take it seriously.” Kevin 21, SlimrChat member