Messed up your Wegovy injection? Here's what to do

Step 1, Stop and assess what actually went wrong

Most injection errors fall into one of a handful of categories: wrong site, uncertain depth, a pen that clicked but looked different to usual, medication visible on the skin after the injection, or a pen that simply didn't feel right. Before doing anything else, work out which of these describes your situation.

A common misconception is that any medication you can see on the skin after injecting means the dose is gone. In practice, a tiny bead of liquid on the surface doesn't necessarily reflect what was absorbed underneath, subcutaneous tissue can absorb the medicine even when a small amount is visible at the surface. That said, you cannot know precisely how much was delivered, which is why the guidance is clear: do not inject again to top up.

The three approved injection sites for Wegovy are the abdomen (at least a few centimetres from the navel), the front of the thigh, or the upper arm. Rotating between these on a weekly basis reduces the chance of site reactions. If you injected closer to the navel than usual or chose an unusual spot, that is unlikely to have prevented absorption, but it is worth noting for next time. The NHS's semaglutide guidance covers approved sites and technique in plain language.

Step 2, Decide whether this counts as a missed or partial dose

If the dose counter on your pen moved to zero (or to the expected end position), the pen dispensed what it was designed to dispense. A successful click and a counter that moved to the correct number is the best evidence you have that the injection completed. Skin-surface droplets in that case are likely moisture from the injection site itself, or a tiny amount that didn't enter the skin, not the whole dose.

If the counter did not move, or the pen jammed mid-injection, you have a more uncertain situation. Do not attempt a second injection from the same pen or a new one without speaking to your prescriber first. Guidance on what counts as a missed Wegovy injection (and how the day-of-week rule works) is worth reading alongside this page, because the approach depends on how much time has passed since your scheduled injection day.

One practical rule from the Wegovy Patient Information Leaflet: if you missed or are unsure about a dose and it is within 5 days of your scheduled injection day, you can take it when you remember. If more than 5 days have passed, skip it and continue on your usual day the following week. Always verify this against your own leaflet or prescriber's advice, because clinical circumstances vary.

Step 3, Troubleshoot technique to prevent it happening again

Technique errors are the most common reason patients feel something went wrong, and they are almost always fixable. The main ones are: not holding the pen firmly against the skin before pressing the button, lifting the pen before the count reaches zero (the Wegovy pen requires you to hold it in place for several seconds after pressing), and injecting through clothing, which affects the angle and skin contact.

Pinching the skin before inserting the needle is not required for every pen or every person, but it can help if you have less subcutaneous tissue at the chosen site. Rotating sites each week also keeps skin tissue healthier and more receptive. If you find the Wegovy pen itself confusing (particularly around the dose window and the needle cap) the Patient Information Leaflet included in your pack provides step-by-step illustrated guidance. It is also worth knowing what happens if your Wegovy freezes, since temperature damage to the pen can affect how it behaves during injection and may explain unusual results. Keeping a fresh supply of alcohol swabs to clean the site beforehand is a simple habit that reduces infection risk and gives you a clear, dry surface to work with.

If you're experiencing persistent side effects after a suspected over-injection, or any unusual symptoms (particularly severe stomach pain that radiates towards the back) seek medical attention promptly. The MHRA's Yellow Card scheme is the right place to report unexpected pen behaviour or suspected product faults.

When to contact a prescriber

Most injection mix-ups don't require urgent action, but some situations do warrant a call or message to your clinical team. These include: the pen malfunctioned or looks damaged, you're experiencing symptoms that concern you after the injection, you took two doses in the same week thinking you'd missed one, or you're switching sites because of persistent soreness and want to know the safest approach.

At nume, our prescribers are available for aftercare queries seven days a week. If something felt wrong with an injection and you're not sure what to do next, that's exactly what the aftercare service is there for, you don't need to wait until your next scheduled review. For broader questions about what Wegovy is prescribed for or how the treatment works, those are covered separately.

If the issue is cost-related and you're wondering whether this is all worth it, our Wegovy price comparison page gives an honest overview of what private treatment currently costs in the UK and what a legitimate service should include. And if you're still at the stage of weighing up weight-loss treatment options more broadly, that's a useful starting point.