The best way to inject Wegovy: a practical guide

Does it matter where on my body I inject?

Yes, and more than many people realise. The three licensed injection sites for Wegovy are the abdomen (at least 5cm from the navel), the front of the thigh, and the upper arm. Each site absorbs semaglutide reliably, so the choice often comes down to what's practical for you on any given day, the abdomen is easiest to self-inject, while the upper arm usually requires help from someone else.

Rotating within and between sites is the part that's easy to skip when life gets busy. Injecting repeatedly into the same small patch of skin causes lipohypertrophy, lumpy, thickened tissue that absorbs medicine unpredictably. A simple system helps: move a few centimetres from last week's spot, or rotate through three or four fixed zones across the sites you use. If you want to dig into how site choice affects your results, our guide to selecting the best injection site covers this in more detail.

Avoid injecting into skin that is bruised, scarred, irritated or actively stretched. If you're wondering about marks already on your skin, what happens if you inject near a stretch mark is something patients ask us regularly.

What does good injection technique actually look like?

The Wegovy pen is pre-filled and pre-set; there's nothing to draw up or measure. That said, a few steps make a genuine difference to comfort and confidence.

First, take the pen out of the fridge roughly 30 minutes before you plan to inject. Cold semaglutide is not dangerous, but it stings more and feels thicker going in. Let it reach room temperature sitting on a clean surface, don't try to warm it in your hands or under hot water. While you wait, wash your hands thoroughly with soap and water.

Clean the skin at your chosen site with an alcohol swab and let it dry completely, 10 to 15 seconds is enough. Wet skin can sting. You can learn the broader technique principles that apply across semaglutide pens if you've switched from or are comparing products.

Pinch a fold of skin gently between your thumb and two fingers if you're injecting the abdomen or thigh, this lifts the fatty tissue away from muscle. Press the pen flat against the skin, not at an angle, then press and hold the button until the yellow indicator bar reaches its end and you hear or feel a click. Keep the pen in place for ten full seconds before removing it. That pause lets the dose clear the needle tip. No aspiration (drawing back the plunger) is needed; subcutaneous injections don't require it.

Safely disposing of your used pen is non-negotiable. A 1-litre sharps container is the correct receptacle, seal it and return it to a local pharmacy or council drop-off point when three-quarters full.

When in the week should I do my injection?

Wegovy can be injected on any day of the week, at any time of day, with or without food. The only rule is consistency: aim to inject on the same day each week so the interval between doses stays close to seven days. Life rarely goes exactly to plan, which is why semaglutide's prescribing information allows a window of up to two days either side if you miss your usual day, but the specifics of managing a missed or delayed dose should always come from your prescriber and the Patient Information Leaflet, not from online content.

Many people tie their weekly injection to something predictable: Sunday evening, Monday morning before work, the same day as a regular gym session. Choosing the best day to inject Wegovy is worth some thought because, during the early weeks of treatment, some people experience a few hours of mild nausea after the dose, picking a day that gives you a quieter window can help with that.

If you're away from home or planning a trip, storage rules become more pressing. Wegovy must be refrigerated between 2°C and 8°C during storage; once in use, your pen can be kept at room temperature for a limited period per the Patient Information Leaflet. Travelling with Wegovy needs a bit of advance planning, especially through airports.

What should I do if the injection hurts or something looks wrong at the site?

Some mild redness, itching or a small lump at the injection site in the hours after is normal and usually settles on its own. It's your body responding to a foreign substance under the skin, not a sign that anything has gone wrong. Rotating sites consistently tends to reduce this over time.

What's less typical: significant swelling, persistent redness, warmth or pain that doesn't settle within a day or two. If you see any of those, contact your prescriber. The same applies if you notice the pen didn't complete its injection (the indicator bar didn't move fully, or the window still shows liquid) because a partial dose affects your whole weekly rhythm, not just that injection.

Wegovy's most common side effects are gastrointestinal: nausea, loose stools, constipation, or an uncomfortable sense of fullness. These are most noticeable in the first few weeks at a new dose level and typically ease as your body adjusts. Severe, persistent stomach pain that spreads toward your back is different, seek urgent medical attention and mention you're taking semaglutide. You can report any suspected side effects through the MHRA's Yellow Card scheme.

If you're still deciding whether Wegovy is the right treatment, the full Wegovy overview covers eligibility, how the medicine works and what to expect. And if you're ready to speak to a prescriber, check your eligibility with our clinical team, consultations are free, with no waiting list.