How to use the Wegovy injection pen, step by step

The night before (and the morning of): what to check first

Picture this: it's Monday evening and your weekly injection day is tomorrow. Before you go to bed, take the Wegovy pen out of the fridge so it has time to come up to room temperature. Injecting a cold solution is more likely to sting, and the pen mechanism works smoothly when it isn't chilled. The NHS patient guidance for semaglutide (Wegovy) confirms the pen should be brought to room temperature before use; your leaflet will state the maximum time it can stay out safely, so note that and don't leave it longer.

While you're at it, check the dose window. The small number visible through the pen's window tells you which dose is loaded. If you're on 0.25 mg at the start of treatment, you'll see that figure. Later, as your prescriber moves you through the titration schedule, the dose displayed will change. Never try to adjust the number yourself, the pen is pre-set.

Gather what you need: a fresh needle, an alcohol swab, and your sharps container. If you're running low on consumables, medical-grade alcohol swabs are available through our pharmacy. Having everything laid out before you start means you won't be hunting around mid-step. That's a small thing, but it makes the process calmer.

The injection itself: sites, technique and the hold

Wash your hands thoroughly, then choose your site. Three are suitable for Wegovy injections: the abdomen (at least a couple of centimetres away from the navel), the front of the thigh, or the outer upper arm. Rotating between these (and between different spots within each site) reduces the chance of skin changes building up in one area.

Swab the chosen spot and let it dry. Attach a fresh needle to the pen, remove the outer and inner needle caps, and if you want a closer look at each of these steps, our guide on how to use the Wegovy pen walks you through the process in detail, including the air-shot (the flow-check step described in your leaflet) to confirm the pen is primed and ready. Then place the needle tip flat against the skin and press the injection button fully until you hear a click. The critical part: keep the pen pressed firmly in place and count to six seconds before removing it. That hold allows the full dose to be delivered. Lifting the pen away too early is the most common reason people find the dose window hasn't fully moved on.

Once you've removed the pen, do not rub the site. Replace the outer needle cap carefully, unscrew the used needle, and dispose of it straight into a sharps bin, never recap with the inner cap alone or place loose needles in a bag. Attach a new needle only at your next injection; leaving a needle attached between doses can introduce air bubbles and affect accuracy.

What to do if something doesn't go to plan

A drop of blood or a small bruise at the site is normal and not a reason for concern. If you notice the skin looks inflamed for more than a day or two, move to a different area next week and mention it when you next speak to your prescriber.

Missed a dose? The general principle for semaglutide is that you can take the missed injection within five days of the day you meant to. After five days, skip it and continue with your next scheduled dose. Your Patient Information Leaflet states this precisely, follow the leaflet rather than any general guidance, and speak to your prescriber if you're unsure. For more detail on how to use the pen across all your doses, our guide to using Wegovy pens covers the device mechanics in full.

If you experience severe or persistent stomach pain that reaches through to your back, stop and seek urgent medical attention. The MHRA highlighted acute pancreatitis as a known but infrequent side effect of GLP-1 medicines in its January 2026 Drug Safety Update; this symptom warrants prompt assessment, not a wait-and-see approach. Other signs that need medical review include signs of an allergic reaction, or symptoms of dehydration after prolonged nausea or vomiting.

Keeping your treatment on track week to week

Try to inject on the same day each week, it builds a habit and keeps the dosing interval consistent. Most people pick a day that's easy to remember: the start of the working week, or a weekend morning when there's no rush. If a bank holiday or a holiday abroad shifts things by a day, that's fine; just don't take two doses within three days of each other. Planning ahead matters if you're travelling, because the pen needs refrigeration. Pack it in an insulated cool bag with an ice pack for the journey.

Wegovy is titrated through a schedule your prescriber sets, starting at 0.25 mg and moving upward at roughly four-weekly intervals. If you'd like a full walkthrough of the process from your first dose onwards, our page on how to use Wegovy takes you through each stage in detail, including what to expect as your dose increases. If side effects feel unmanageable, talk to your prescriber before deciding to stop, there are options that don't mean abandoning treatment.

Cost of treatment is a common question at this stage. If you'd like context on what private prescriptions typically include, our Wegovy pricing page sets out what to look for and how to compare providers fairly. And if you're curious how Wegovy sits among the broader options available, our weight-loss treatment overview covers the landscape. When you're ready to speak to a prescriber, starting your free consultation is the first step, a named clinician, not an automated system, will review your details the same day.