Wegovy self-injection: what you need to know before your first dose

Choosing the right injection site for you

The first real decision is where. The abdomen is the site most people start with: there is usually enough subcutaneous (fatty) tissue, it is easy to reach, and the injection can be given without help. The outer thigh works equally well and is a good alternative if your abdomen is sore or you simply prefer it. The upper arm is the third option, though it is harder to administer yourself, if you choose it, a partner or carer may need to help.

Whichever site you use, rotate within it. If you always inject the same spot, you can develop fatty lumps under the skin (lipohypertrophy) that may affect how the medicine is absorbed. A common approach is to divide the abdomen into imaginary quadrants and move around them week by week. Avoid skin that is bruised, tender, red, or broken.

Inject into the fatty tissue beneath the skin, not into muscle. Pinching the skin gently before inserting the needle can help, particularly for people who are less overweight and have less subcutaneous tissue. The Wegovy injection overview on this site covers the pen mechanics in more detail if you want a step-by-step walkthrough alongside this guidance.

Timing: building injection day into your week

Wegovy is a once-weekly injection, and you can choose any day. The only firm rule is to keep roughly seven days between doses. Many people pick a day that carries a natural reminder, a Monday evening, or Sunday morning before the week gets busy. What matters more than the day is that you are consistent.

If you miss a dose and it is within five days of the missed injection, take it as soon as you remember. If more than five days have passed, skip it and resume on your normal day. Never take two doses to compensate. The guide to self-injecting semaglutide covers missed-dose scenarios in practical terms, though your Patient Information Leaflet and prescriber are always the right authorities here, this page is educational and not a substitute for their guidance.

Storage matters too. Keep pens refrigerated at 2–8°C when not in use. If you need to take one out of the fridge, the SmPC gives an exact room-temperature window, always check the leaflet rather than relying on a figure quoted online, because that window can differ by product version. Some people leave the pen out for twenty minutes before injecting; a room-temperature pen can feel slightly more comfortable than a cold one.

Before you inject: the checks that count

A few seconds of preparation makes the process both safer and more comfortable. Clean the chosen skin site with an alcohol swab and let it dry before inserting the needle, wet skin can sting. Check the pen window: the liquid should be clear and colourless or faintly yellow, with no particles. If anything looks unusual, do not use it and contact your pharmacy.

Remove the pen cap only when you are ready to inject. Press the pen firmly against the skin so the auto-needle engages, then press and hold the dose button. Hold for the count specified in your leaflet (usually around ten seconds) before removing. You may hear a click when the dose is complete; the window often changes colour to confirm delivery. If you are uncertain whether the full dose went in, do not re-inject, contact your prescriber for advice.

Once finished, place the used pen straight into a sharps container. It should never go loose into a recycling bin or general waste. Local pharmacies, including many NHS ones, usually accept sealed sharps containers for disposal at no charge. The self-injecting semaglutide page also touches on disposal if you want further detail.

Side effects to watch for in the first weeks

Most side effects with Wegovy are gastrointestinal. Nausea is the most commonly reported, followed by constipation, loose stools, indigestion, and occasional vomiting. These tend to be most noticeable in the days after starting or after a dose increase, and they usually ease as your body adjusts, often within a couple of weeks. Eating smaller meals, avoiding rich or fatty food, and staying well hydrated helps considerably.

The Wegovy injection technique guide notes that injection-site reactions (redness, itching, or a small lump at the site) are also common and almost always minor. Rotating sites helps prevent them from becoming persistent.

A handful of symptoms warrant prompt medical attention. Severe stomach pain that reaches towards the back and does not pass is one of them, the MHRA highlighted acute pancreatitis as a known, infrequent but serious risk in a Drug Safety Update issued in January 2026. Seek urgent help if you experience this, significant chest pain, signs of a serious allergic reaction (swelling of the face, tongue or throat, difficulty breathing), or any sudden change in vision.

Suspected side effects can be reported directly to the MHRA via the Yellow Card scheme, patients can do this themselves, not just clinicians. It is worth knowing about, even if you never need it.

One note on cost: Wegovy is a private prescription medicine for most people in the UK, and prices vary between providers. If you want to understand exactly which version of the treatment you would be receiving, the Wegovy injection S page sets out the specific product details clearly. If the financial side is on your mind, the Wegovy cost breakdown explains what a legitimate price should include, and what suspiciously low prices often leave out.

If you are thinking about starting Wegovy or have questions before your first injection, our prescribers are here to help. Start your free consultation and a GPhC-registered prescriber will review your case the same day.