Administering Wegovy: a step-by-step guide to your weekly injection

The moment the box arrives, what you're working with

Your Wegovy arrives in plain, unbranded packaging via DPD, with tracking on your phone so you know exactly when to be in. Inside you'll find one or more pre-filled pens, each holding a single dose at your prescribed strength. The pen is designed to be handled without medical training: a capped needle, a dose window, and an injection button. Before anything else, read through the Patient Information Leaflet that comes with it. It is the definitive reference for your specific pen and dose.

Keep pens in the fridge (2–8°C) until you're ready to use one. Take the pen out roughly 30 minutes before your planned injection time so it reaches room temperature, a cold injection can be more uncomfortable. Check the liquid through the dose window: it should be clear and colourless or faintly yellow, with no particles floating in it. If it looks cloudy or discoloured, don't use that pen and contact your prescriber or our support team.

The semaglutide overview on our Wegovy page explains how the medicine works in the body, which may help contextualise why consistency in timing matters.

Choosing your injection site, and why rotation isn't optional

Wegovy can be injected into three areas: the front of your abdomen (at least 5 cm away from the navel), the front of your thigh, or the outer area of your upper arm. Each is equally effective, so the choice comes down to practicality and personal comfort. Many people start with the abdomen because it's easiest to see and reach.

Rotation matters more than most people realise. Injecting repeatedly into exactly the same spot can cause a hardened patch of tissue (lipohypertrophy) that slows absorption and makes injections less effective over time. A practical system: move to a fresh spot within the same area each week, then cycle through the three areas across different doses.

Clean the skin with an alcohol swab and let it dry fully before injecting. Pinch a small fold of skin, press the pen firmly against it, and activate the injection according to the steps for administering Wegovy for your pen model. Hold it in place for the count the leaflet recommends (usually around 10 seconds) before removing. You might see a tiny spot of blood or a small red mark; both are normal.

If you'd like a visual reference, a step-by-step injection video can help make the process feel more familiar before your first dose.

Timing your dose, and what to do if the day shifts

Pick a day of the week that suits your routine and stick to it. Sunday evening after dinner, Thursday morning before work, whatever you'll actually remember. Consistency means your body gets a steady, predictable rhythm of the medicine.

Life sometimes intervenes. If you miss your usual day, you can take that week's dose as soon as you remember, provided the next scheduled dose is still at least 48 hours away. If you're close to that window, skip the missed dose and continue on your regular day. Never take two doses to compensate. The Patient Information Leaflet for your pen contains the exact missed-dose guidance, and it's the text your prescriber has reviewed alongside your treatment, if in doubt, the guidance on when to administer Wegovy covers timing questions in more detail.

Used pens should go straight into a sharps disposal container, not into household waste or recycling. Details on cost and where to begin if you're not yet on treatment are covered on our Wegovy cost and pricing page, worth reading before you start, so the ongoing practicalities of supply feel clear.

Side effects to expect, and when to seek help

The most common side effects after administering Wegovy are gastrointestinal: nausea, loose stools, constipation, indigestion, and reflux. These tend to be most noticeable in the first few days after a dose, particularly when you're starting out or moving to a higher strength. For most people they settle within a week or so. Eating smaller meals, staying well hydrated, and avoiding very fatty foods on injection day can all help.

Injection-site reactions (redness, mild swelling, or brief discomfort at the spot) are also common and usually resolve quickly. If you want a full walkthrough before your next dose, our directions for administering Wegovy set out each step clearly and can help you refine your technique. Rotating your sites consistently (as above) reduces the likelihood of these becoming persistent.

Seek medical help promptly if you develop severe stomach pain, especially pain that spreads to your back and doesn't ease off. This can be a sign of pancreatitis, which is a known but infrequent side effect that requires urgent assessment. The NHS medicines guidance for semaglutide lists the full range of side effects and the specific symptoms that need urgent attention.

Any suspected side effect can be reported through the MHRA Yellow Card scheme, which monitors the safety of all medicines in the UK. If you have questions about a reaction, our clinical team is available for aftercare support seven days a week.

If you haven't yet started treatment and want to understand whether Wegovy is suitable for you, check your eligibility through a free consultation, a GPhC-registered prescriber will review your details the same day.