How to Use the Wegovy Single-Dose Pen: A Step-by-Step Guide

Step 1: Prepare your pen and choose your injection site

Take the pen from the fridge and let it sit at room temperature for the time specified in your patient information leaflet before injecting, a cold pen can make the injection more uncomfortable. While you wait, wash your hands thoroughly with soap and water.

Check the label to confirm it is the correct strength for your current stage of treatment, and inspect the liquid through the viewing window. It should be clear and colourless to slightly yellow. If you see particles, cloudiness or discolouration, do not use that pen; contact your prescriber or pharmacist.

Choose one of the three licensed injection sites: the abdomen (at least a few centimetres from the navel), the outer thigh, or the upper arm. Each week, rotate to a different spot within or between these areas. Rotation matters, injecting repeatedly into the same patch of skin can cause changes to the tissue beneath. Clean the chosen area with an alcohol swab and allow it to dry fully before injecting.

The single-dose pen has a covered needle that activates when you press it against your skin, so there is no cap to remove or needle to attach separately. This differs from the multi-dose format; if you have previously used the standard four-dose Wegovy pen, take a moment to read through these steps afresh rather than relying on muscle memory.

Step 2: Inject and complete the dose

Pinch a fold of skin at the chosen site and hold the pen firmly against it at a 90-degree angle. Press and hold the injection button until you hear or feel a click, then continue to hold the pen in place for the count specified in your patient information leaflet (typically around ten seconds) to ensure the full dose is delivered. You will see the plunger move in the viewing window when the dose is complete.

Withdraw the pen without pressing on the skin and release the pinched fold. A small amount of bleeding or a tiny bruise at the site is normal and not a cause for concern. Do not rub the area after the injection.

A question our prescribers hear most weeks is whether it matters which day of the week you inject. The answer is no, provided you keep to the same day each week. If you miss a dose and fewer than five days remain before your next scheduled injection day, skip the missed dose and resume your normal schedule, do not inject twice in one week. Always refer to the patient information leaflet or speak to your prescriber if you are unsure; our team is available seven days a week through aftercare support.

For anyone new to the injection process, our guide to using the Wegovy 0.5mg pen walks through the technique in detail if you want step-by-step guidance specific to that strength. The earlier pen formats cover the same core technique; our guide to using the Wegovy 1mg pen walks through the pinch-and-hold method in detail if you want additional context from a lower-dose starting point.

Step 3: Dispose of the pen correctly and store the next one

The single-dose pen locks after use so it cannot be reused. Place it immediately into an approved sharps container, not in the recycling bin or general waste. Full sharps containers should be taken to a pharmacy or local authority collection point for safe disposal. If you do not yet have a container, a one-litre sharps container is available from our pharmacy and is the right size for home use.

Store unused pens in the fridge at 2–8°C, away from the freezer compartment and out of direct light. If a pen has been frozen, do not use it. The patient information leaflet specifies the maximum time a pen may be kept outside the fridge before it must be discarded; always follow that guidance rather than a general estimate, as storage tolerances differ slightly across strengths.

Keep pens in their original carton until use and out of reach of children. Travel with a small cool bag if you are away from home for more than a few hours, and check airline rules on carrying sharps in your hand luggage before you fly. You can find broader practical detail about the pen format itself on our Wegovy single-dose pen overview.

Side effects to know about and when to seek help

The most common side effects of semaglutide are gastrointestinal: nausea, loose stools, constipation, indigestion and burping. These tend to be most noticeable in the first days after a new dose level begins and usually ease within one to two weeks as your body adjusts. Eating smaller portions, avoiding fatty or heavily spiced food, and keeping well hydrated all help.

Seek medical help promptly if you develop severe stomach pain that spreads to your back, with or without vomiting. This pattern can indicate acute pancreatitis, which the MHRA highlighted in a Drug Safety Update for GLP-1 medicines in January 2026. It is uncommon but serious. Other symptoms that warrant urgent attention include signs of an allergic reaction (swelling of the face or throat, difficulty breathing), yellowing of the skin or eyes, or significant dehydration from prolonged vomiting or diarrhoea.

Injection-site reactions such as redness, itching or a small lump are common and almost always mild. Rotating your injection site each week is the most effective way to reduce them. If a reaction is spreading, warm to the touch or failing to settle within a few days, speak to a pharmacist or GP.

You can report any suspected side effect directly to the MHRA at yellowcard.mhra.gov.uk. Reporting helps build the safety picture for all patients using these medicines.

For context on how the titration schedule works alongside these injection steps, the Wegovy doses guide covers the full escalation pathway from the starting 0.25mg level through to the maximum 7.2mg dose, and if you are currently on the second step of treatment, our Wegovy 0.5mg page has information specific to that strength. And if you are still weighing up whether Wegovy is the right fit for your situation, our weight-loss treatment overview sets out the options side by side.