The best area to inject Wegovy, and how to rotate sites properly

Step 1, choose your starting site

Most people begin with the abdomen because it is the easiest area to reach and visualise. Pinch a fold of skin at least 5 cm (roughly two finger-widths) away from the navel, avoiding the band of the waistband and any scar tissue. The needle goes in at roughly a 45-degree angle into the fatty tissue beneath the skin, subcutaneous, not into muscle.

The front and outer thigh works well if you find the abdomen uncomfortable or if the skin there becomes irritated. Aim for the mid-section of the thigh, not the inner surface. Some patients find this easier when seated, which relaxes the muscle and lifts the fatty layer slightly.

The outer upper arm is the third option. It is harder to self-inject here, so this site is more practical if someone else is administering the injection. If you do use the upper arm yourself, a mirror can help you confirm placement. Avoid the deltoid muscle itself, the injection should be into the soft tissue on the outer, posterior surface of the upper arm. For a closer look at the technical differences between these sites, the guide to the best Wegovy injection site covers them in detail.

Wherever you start, make a note of the location. Many patients find a simple app or a pen mark on a diagram easier than trying to remember.

Step 2 (prepare the skin and the pen

Clean the chosen spot with an alcohol swab and let it dry completely) injecting through wet skin can sting. Attach a fresh needle to the pen before every injection; reusing needles increases the risk of blockages and blunts the tip, which makes the injection more painful than it needs to be.

Check the medicine in the pen's window: it should be clear and colourless. If you see particles or cloudiness, do not inject, contact your prescriber. The Wegovy pen is pre-filled with four weeks of doses, and the dose is pre-set, so there is no dial to adjust. Press the pen firmly against the skin, hold for a full six seconds after the injection, then withdraw slowly. The needle shield will extend automatically.

Before you inject, read through the pen's handling guide so you are confident with each part of the device. A small amount of bruising at the site is normal and usually settles within a day or two. The NHS medicines information for semaglutide covers what to expect from injection-site reactions, and the NHS semaglutide page is a useful reference to bookmark alongside your Patient Information Leaflet.

Step 3 (rotate every week without exception

Rotation is where many patients slip up) not because the advice is complicated, but because they gravitate to the same comfortable spot. Injecting into skin that is already slightly tender from last week's dose can cause a firm lump under the surface called lipohypertrophy. Once that develops, absorption becomes unpredictable, which undermines the whole point of a carefully titrated treatment.

A practical system: divide each site into a rough grid of zones and move one zone along each week. You can also cycle between sites (abdomen one week, thigh the next, opposite side of the abdomen the week after) rather than staying within one area. The key is that the needle never lands in exactly the same square centimetre two weeks in a row. For patients thinking about choosing a consistent weekly injection day, a fixed day makes rotation planning much simpler.

If you are new to Wegovy, timing tends to settle into a rhythm once you pick a day and a starting site. Some people tie the injection to something predictable in the week, and if you are unsure about what time of day works best for your Wegovy injection, that can be worth thinking through before you settle on a routine. One thing worth knowing: if your injection day lands on a public holiday or you are travelling, the pen can be taken slightly earlier or later within a short window, check your Patient Information Leaflet for the precise allowance, or ask your prescriber. Keeping a sharps container wherever you usually inject means used needles are disposed of safely without a second thought.

When to ask for help, and how to report a reaction

Mild redness and a small amount of itching at the injection site are common and usually resolve within hours. Persistent swelling, pain that worsens over 48 hours, or a spreading redness are signs to contact your prescriber or GP rather than waiting for the next routine check-in. An allergic reaction (widespread rash, difficulty breathing, rapid heartbeat) needs emergency medical attention.

Patients on Wegovy can also report suspected side effects directly to the MHRA via the Yellow Card scheme. This is especially valuable for injection-site reactions that seem unusual, because the MHRA uses these reports to monitor medicines across the population.

Questions about your specific technique, skin changes, or whether a reaction is normal belong with your prescriber, not a forum. If you are wondering whether Wegovy is the right treatment to begin with, or how it compares to other licensed options, the weight-loss treatment overview sets out the full picture. And if cost is something you are weighing up, our Wegovy pricing page explains what an honest, complete private prescription actually includes.

If you have not yet started treatment and want to understand whether you are eligible, check your eligibility with our prescribers through a free consultation. A named clinician reads every submission the same day, no queues, no algorithms.