Wegovy Instructions: How to Use Semaglutide the Right Way

The biggest misconception: that the pen just needs to be jabbed in and pressed

Many people assume a pre-filled injector pen is entirely foolproof, point it at the skin, press, done. In practice there are several steps before the needle meets skin, and skipping them is the most common source of incomplete doses and injection-site reactions. The official wegovy instructions for use, published in the Patient Information Leaflet and on the electronic Medicines Compendium (eMC), walk through each step in sequence. Detailed guidance on wegovy administration covers the full process, but the essentials are below.

First, remove the pen from the fridge and let it sit at room temperature for around 30 minutes, injecting cold medication is one of the most reliable ways to make the site sting unnecessarily. Check the liquid through the window: it should be clear to slightly yellow and free of particles. If it looks cloudy, discoloured, or you can see floating matter, do not use that pen; contact your pharmacy.

Remove the pen cap and clean the chosen injection site with an alcohol swab. Pinch the skin lightly if you are lean, this is less often necessary for abdominal injection sites. Press the pen firmly against the skin at a 90-degree angle, press the injection button, and hold it in place until the flow indicator stops. A click at the start and a locked indicator window at the end confirm a complete dose. That final hold is the step most commonly rushed. It typically takes around ten seconds.

There is also a video walkthrough of the wegovy injection technique that some people find easier to follow than written steps alone.

Dose schedule: what your prescriber sets, not what you adjust

Wegovy semaglutide dosing instructions follow a fixed escalation set by the prescriber, not chosen by the patient. The licensed UK schedule begins at 0.25mg per week for the first four weeks. This is a tolerability step, its job is to let your digestive system adjust before any meaningful weight-management effect begins. That matters because the most common side effects (nausea, vomiting, diarrhoea) are most likely to show up in the early weeks and tend to ease as the body adapts.

From there, the prescriber typically moves to 0.5mg, then 1.0mg, then 1.7mg, before reaching the 2.4mg maintenance dose. Each step lasts at least four weeks. The MHRA's approval of a 7.2mg higher-dose option (and a dedicated single-dose 7.2mg pen, approved on 14 April 2026) means some patients may eventually be titrated beyond 2.4mg, but only under clinical direction. If you are considering a move in dose, that conversation happens with your prescriber, not by reading a PDF.

Missing a dose happens. The general guidance is: if fewer than five days have passed since the missed dose, take it as soon as you remember, then continue on the usual day. If five or more days have passed, skip that week and carry on with the next scheduled dose. Never take two doses to compensate. Your Patient Information Leaflet has the exact wording; your prescriber or pharmacist can clarify if you are unsure. Changing your injection day is also possible, consult your leaflet for the minimum gap required between doses on a changed schedule.

If you are curious about whether semaglutide will show up in your bloodwork, that is a question worth reading up on before any routine tests. For a fuller picture of how semaglutide works at a molecular level, the overview of semaglutide's structure and mechanism explains what the GLP-1 receptor pathway does in practice.

Injection sites, skin care, and storage

Three sites are approved: the abdomen (at least a few centimetres from the navel), the front of the thigh, and the outer upper arm. Rotating between and within those areas matters. Using the same spot repeatedly can cause lipohypertrophy (localised thickening of the fatty tissue) which affects how the medicine absorbs. A simple habit is to track which site you used last week.

The full wegovy overview page sets out broader context on how the treatment is used in the UK, but on the practicalities: do not inject into skin that is bruised, tender, scarred, or irritated. Do not rub the site after injection. If you notice persistent redness, swelling, or a hard lump at an injection site, let your prescriber know.

On storage: pens live in the fridge, between 2 and 8°C. They can be stored there until the expiry date printed on the label. For the specific number of days a pen may be kept outside the fridge once removed, check your Patient Information Leaflet, the window is defined there, and stating a number here without qualification would be misleading if the approved figure changes. Keep pens out of direct sunlight and away from freezing temperatures. A frozen pen should not be used.

Used pens are sharps and must be disposed of in a sharps bin, never in household recycling or general waste. Your pharmacist can advise on local sharps disposal.

Side effects to know about, and when to get medical help

The NHS notes that the most common side effects with semaglutide are gastrointestinal: nausea, vomiting, diarrhoea, constipation, and indigestion are all reported, particularly during the early weeks or after a dose increase. These generally settle as the body adjusts. Eating smaller meals, staying well hydrated, and avoiding fatty or spicy food during the first weeks can help. Fatigue and headache are also possible.

Some side effects need prompt medical attention. Severe, persistent stomach pain that spreads to the back (with or without vomiting) may indicate pancreatitis, a known but infrequent serious reaction. The MHRA highlighted this in a Drug Safety Update for GLP-1 medicines in January 2026 and recommends stopping the medicine and seeking urgent care if these symptoms appear. Other situations that warrant calling 111 or going to A&E include signs of a severe allergic reaction (swelling of the face or throat, difficulty breathing) and symptoms of significant dehydration from prolonged vomiting or diarrhoea.

You can report any suspected side effect directly to the MHRA via the Yellow Card scheme. Patients, carers, and healthcare professionals can all submit reports, the link above takes you there.

If you have questions that fall outside what the leaflet covers, our prescribers are available. The downloadable patient instructions resource is a useful reference to keep alongside your pen. And if you are still in the early stages of deciding whether semaglutide is right for you, the weight-loss treatment overview lays out the licensed options available through nume.

Wegovy is a prescription-only medicine. Clinical assessment by a GPhC-registered prescriber is required before any treatment can start. If you are ready to have that conversation, start your free consultation and a prescriber will review your details the same day.