Wegovy Injection Tutorial: How to Inject Safely and Confidently

What the SmPC and NHS guidance say about injection technique

The prescribing information for Wegovy (held on the electronic Medicines Compendium (eMC)) sets out the technique that underpinned every clinical trial. Before you begin, take the pen from the fridge and leave it at room temperature for roughly 30 minutes; a cold pen can make the injection sting more than it needs to. Wash your hands thoroughly. Remove the pen cap and check the window: the liquid inside should be clear and colourless, or very slightly yellow. If it looks cloudy, has particles floating in it, or is a stronger colour than expected, do not use that pen and contact your prescriber or pharmacy.

That quick visual check takes under a minute, and it is the single habit most worth building into your routine.

Attach a new needle, peel off both caps, then clean the injection site with an alcohol swab and let the skin dry completely before injecting, injecting through wet skin is less comfortable and can sting. Pinch a fold of skin gently with your free hand, hold the pen at a 90-degree angle and press it flat against the skin. Push the button, keep the pen pressed in place until the injection counter shows zero, then hold for a further five to ten seconds. Release the skin fold, withdraw the pen and dispose of the used needle in a sealed sharps container.

Choosing and rotating your injection sites

Three anatomical areas are licensed for Wegovy: the abdomen, the front and outer thigh, and the outer upper arm. Each has practical advantages. The abdomen is easiest to access and easiest to see clearly. The thigh is a good option for people who self-inject alone at home. The upper arm is manageable for most people and is the site described in more detail on the guide to arm injections if that is your preference.

Rotation matters more than most people realise. Injecting into the same small spot repeatedly can cause a localised build-up of fat tissue (lipohypertrophy), which reduces how reliably the medicine is absorbed. A practical system is to mentally divide each site into a grid and move one square along each week. Keep the abdomen injections at least five centimetres from the navel, and avoid any area of skin that is sore, bruised, scarred or has any sign of a skin condition.

If you are taking an oral contraceptive pill, the NHS England guidance on weight-management injections notes no current evidence that semaglutide reduces pill absorption, unlike the equivalent guidance for tirzepatide. Your prescriber will have covered contraception at consultation, but it is worth raising any questions at your next clinical review. For a broader look at how semaglutide compares with other weight-loss injections, that page sets out the differences clearly.

Managing common first-pen experiences

The most frequently reported side effects in the STEP 1 trial were gastrointestinal: nausea, diarrhoea, vomiting and constipation, occurring most often in the first weeks of treatment or after a dose increase. For most participants these were mild to moderate and settled as the body adjusted. Smaller, lower-fat meals tend to ease nausea; staying well hydrated matters particularly if diarrhoea occurs.

Injection-site reactions such as redness, itching or minor bruising do happen, typically shortly after the injection and resolving within a day or two. They are usually linked to technique or rotating too slowly between sites. A blunt or reused needle is a common culprit: a fresh needle every time significantly reduces local discomfort.

There are symptoms that warrant urgent medical attention rather than waiting to see if they settle: severe, persistent stomach pain, particularly pain that radiates towards the back, should be assessed promptly as this may indicate pancreatitis, which the MHRA identified as a known but infrequent risk in its January 2026 Drug Safety Update for GLP-1 medicines. Signs of an allergic reaction, including swelling, difficulty breathing or a widespread rash, also need immediate medical attention. For a fuller picture of what to expect and when to act, the semaglutide side-effects guide covers the full profile.

Missed doses and what to do with a late injection

Life happens and an injection gets forgotten. The Patient Information Leaflet advises injecting the missed dose as soon as you remember, provided there are at least five days until your next scheduled injection. If fewer than five days remain, skip the missed dose and resume your normal day. Never inject two doses to make up for one skipped. Your prescriber is the right person to ask if this happens repeatedly or if you are unsure how to handle a specific situation, the how-to guide for Wegovy covers this and other practical questions in more detail.

If you are thinking about starting treatment or are partway through and have questions about your current plan, the team at nume reviews every consultation individually, and support is available seven days a week. You can also read about Wegovy treatment costs if pricing is a factor in your decision. When you are ready, speak to our prescribers through a free consultation, the same day, with a real clinician.